The Office/WMG

Michael Scott will become more mature before he leaves

 * "Threat level midnight", nuff said.
 * As well as "Todd Packer"
 * Judging from the last few episodes before his leave, I'd argue that this is confirmed. I'll copy paste an analysis I wrote on reddit regarding his development:

"Michael Scott is the most well-developed character on television that I can think of...ever. [Edit: I meant to say television comedy here] Every dimension of his being works out beautifully. If any single character on comedic comedy shows the full depth of a person, it's Michael. He is simultaneously a very selfish person, but also very caring. He is very offensive, but also strives to be politically correct (in a very misguided way). He is a fantastic salesman, but a horrible people person. There's a bunch of hypocrisies in his character, but the writing and Steve Carrell's acting handled them very well."

"At his heart, Michael is just a very lonely guy, who wants, above all else, to feel accepted. This is at the heart of almost all of his quirks and problems. Not just that he wants to feel accepted, but also the fact that he is unable to be honest with himself about who he really is. His self-dishonesty leads to him being quite dense with himself and others which leads to him being more isolated from others. It's a viscious cycle."

"Consider the mug on his desk. "World's Greatest Boss". Who gave him that? He did himself. Similarly he put up fake diplomas on the wall, etc. He loves to brag to people about various things in his life (especially his sex life) in order to gain approval from "the guys", and he has shown the tendency to constantly misrepresent reality to make himself feel better. The episode with Dwight's speech? When Dwight did better than him, Michael left and got a beer to avoid it, and then rationalized it away by saying that since Dwight was inspired by him then Michael is a great speaker as well."

"He is a treasure trove of defense mechanisms. All to hide himself from himself. They don't all result in bad things. Because of his tendency to equate work with family, he has intense care for the people at his office....like the time he was the only one to visit Pam's exhibit. No matter how much he upsets people, he always tries to be there for them, like a father, because fathers feel needed and wanted. This kind of acceptance is the one thing he wants in his life, above all else.

Towards the end of his run, he finds true love in Holly, proposes to her, etc. At the last Dundies, everyone there sang to him and gave him a Dundie. The beginning of his last episode he throws the his old mug into the trash and replaces it with the Dundie, symbolizing his realization that he has gained acceptance from his employees. Towards the middle of the episode, he has a small nervous breakdown, resulting in him reaching into the trash and pulling out that old "Best Boss" mug again, until he gets Holly on the phone again to reassure him. This isn't a coincidence...its pretty obvious symbolism. He matured quite a bit throughout the series (despite his antics becoming arguably stupider, he has emotionally matured, I feel), but still has a bit to go. But at least he has someone to go through this struggle with...Holly, and their thousands of kids he will be friends with."

There are no cameramen. The Office employees are just extremely schizophrenic.
Think about it. This is one of the only ways that can really explain how so many episodes are able to feature such intimate personal lives of the employees and the tons and tons of Fridge Logic revolving around the show.

Dunder Mifflin was constructed under a toxic runoff, which has seeped into their water supply. This has led the entire cast to believe that there's an invisible camera person documenting their entire lives. This also explains why many outsiders like David, Holly and Erin never once question the fact that there would be a camera crew at a paper company: they just secretly roll with it.
 * Jossed in Michael Scott's last episode when he takes off his microphone.

Dunder Mifflin Paper Company, Inc. is real.
The Office is a reality TV show focused around the personnel. The format mirrors that of a reality TV show with its "confessions" and everybody being instructed not to "notice" the camera, although people often glance at it and occasionally directly reference it.
 * If this was true, then shouldn't Michael have been fired numerous times over by now? For that matter, almost everyone in the office would be unemployed.
 * Creed has way  more blackmail material than anyone wants to be public. And he gives pieces to other people to ensure it can't all be seized.
 * The producers of the show likely have some influence as well. Producers of Reality TV always do.

Both the British and the American series are in the same continuity.
And eventually, Michael and David will have an all-out duel between each other.
 * Let's hope Dwight and Gareth face off.
 * Dunder Mifflin will be bought out by newly successful British paper company Wernham Hogg, and Tim will be the new VP/CFO/whatever.
 * Parks and Recreation takes place in the same universe as well. When all three shows crossover, there will be a three-way fistfight between David, Michael, and Leslie which will somehow end up with them all in a threesome together. Also Karen Filippelli and Ann Perkins will be revealed to be twins Separated at Birth and they will pull a Twin Switch, Parent Trap style.
 * CONFIRMED!: In "The Seminar" (7x14), Michael meets David in a lobby and they discuss acting techniques.
 * Also, after Michael leaves, David Brent makes a brief return as one of the candidates for Michael's old job.

The cameraman is a Watcher or Watcher-like agent.
To allow him to observe without intruding, although he has been reprimanded for occasionally interfering more than he should. He has the ability to be in multiple places at once, including in front of moving cars. He has the ability to pause time and instantly pull a person aside for a quick interview. We have not heard him speak, which strongly implies that he has telepathic powers; his not speaking limits his influence on those around him, which is why he was chosen. What his true purpose is and what he is seeking to learn is unknown at this time.

Jan is using the Lysistrata Gambit on Michael.
Jan seems to win all of the many arguments the two have because she threatens to withhold sex if she doesn't get her way. It's Michael Scott we're talking about here, but still, there's no other way he could be that whipped. He's tried to use it on her at least once; he probably got the idea from her using it on him.
 * In one episode, Michael used it on Jan to get a raise.

The show is being broadcast in a foreign country.
The "show" has been on the air for several years; yet none of the employees appear to have watched it. (The British version's Christmas special demonstrates that their subjects did.) Jim and Pam's relationship would have been obvious from the get-go; Creed would have been canned any number of times; and Micheal and Jan's secret trysts would have seen the light of day instantly. The (implied) language barrier would also contribute to people giving such honest "confessions" about people they work every day. It airs in Germany. Or Japan.

The show could also be shown in Communist countries as a satire of Capitalism.

In the Officeverse, the show has not yet been broadcast.
The documentary crew is doing a long-term project, like "What will these people be doing in ten years?" This is why they show things outside the office, such as Toby in Costa Rica and Pam at art school.
 * Semi-confirmed, at least as far as Michael Scott's last year. He asked if they would ever start airing it.

The production crew airs the show in a foreign country AND is paying off Dunder Mifflin considerably to continue filming.
With all of the terrible examples of employee and company behavior captured on camera, its a wonder why anyone at DM would still allow it to be taped and broadcast... unless the company is getting something big for it. Being a struggling business in a dying industry, it keeps itself afloat by allowing its branches (largely Scranton) to be filmed for broadcast as a documentary in other countries in exchange for a continual amount of money

This explains why the cameras are allowed in the boardrooms, events, and stockholder meetings of Dunder Mifflin, its all in the contract. It can't be aired in North America so the company's reputation can be protected and all employees have signed away the right to use the footage for any lawsuit. .

The show is a hallucination of Creed
Creed never stopped being homeless, and he eventually went insane. This is why some of the personalities seem so ridiculous that they would've likely been fired several times over - including Creed's. He's acting like he would were he not hallucinating.
 * But Creed's playing himself, so... Uh-oh.

The cameramen aren't a documentary crew at all
They were originally hired by the company to get material to fire Michael Scott. Michael saw them, and they quickly made up the lie about being a documentary crew. The reason he hasn't been fired yet is that he's keeping the "crew" around all the time, and they haven't found any way to escape.
 * But one of them follows Pam to New York to film her at art school. One of them hops on a plane to Costa Rica to see Toby. One of them heads to Utica to talk to Karen before anyone even knows she's trying to hire Stanley. They even follow Michael after he leaves the company (briefly) to form The Michael Scott Paper Company.
 * Could be a way to stave off suspicion and still keep tabs on Micheal. Also to expand the theory Toby could see through the ruse and find this a wrong move of power and wants to keep Michael employed but is foiled unintentionally by Michael. If anything the other employes know this and secretly want Michael fired so they take no part in the Toby/Michael feud. They tell him their secrets because they know he'll spill the beans so they can have a reason to have him fired.

The finale will have the documentary revealed to be a sadistic prank to film a comedy show.
Actors would include Creed, Molly, and the majority of the Scranton branch's clients. The episode will end with a baseball bat heading toward the camera and a Blair Witch Project style screencap saying "These tapes were found buried in the woods outside of Scranton, New York. Attempts to find the producers and the actors filmed have been unsuccessful."
 * If the tapes were found outside of Scranton, NEW YORK, then something REALLY mysterious must have happened!

The documentary we see is the director's cut, not the In-Universe broadcast version
The documentary team signed all sorts of agreements that prohibit them from broadcasting any of the illegal, personal, or remotely interesting things happening in the office. The version of the show being broadcast in the Officeverse is a much more serious and boring documentary of office life. The version we see is put together by the documentary crew for their own enjoyment. This explains why none of the characters appear to have watched the show - the show they see has the relevant events cut out.

Dunder Mifflin is the official paper supplier of all of NBC.
Possibly the rest of GE as well.
 * And also the Sheinhardt Wig Company.

The penultimate episode will see Michael Scott get fired. The Finale will see the first episode of The Office finally hit the air.
The producers of the show had been told to "follow Michael Scott and his friends and employees until he is fired then come back to us with a series". They had expected to maybe get a week of material.
 * At the launch party, Dwight and Michael will engage in Wild Mass Guessing as to what will happen, including the question of whether Jim and Pam will hook up. Pan to Jim and Pam Halpert looking at the camera in a awkwardly ironic fashion. Fade to Black.
 * Confirmed false.

Michael is a high-functioning autistic.
It would explain why his social skills are so lacking, despite being at least somewhat competent in other respects and having received a position as branch manager.
 * He's socially awkward because he didn't have any friends or a father figure when he was growing up. After all, he wanted to be friends with his coworkers.

The camera crew has long since expired their stay, and they are only sticking around and filming because they personally are so curious about what goes on in the office.
Hey, it makes as much sense as anything else.

Marjorie died and her ghost is haunting the office.
Marjorie was an extra for the first few episodes, but in recent seasons she's barely seen. Yet she can somehow be viewed lurking in the back of crowds or lingering just off screen...

The camera crew are shooting a Political documentary that has failed to prove it's intended point.
The intention of the project was to do a profile of a company that was hurt by the economic policies of the Bush Administration. Dunder Mifflin Scranton was picked due to it appearing to be mere months away from total collapse, thus fulfilling his goal of demonstrating that those policies were making things worse. The filmmaker is too proud to abandon the project and is collecting footage until the company does collapse and he can be proven right. The project is currently many millions over budget.

The mug Michael gave Jim is his first step in a lighthearted Plan.
The final scene of the series will show Michael staying behind after everyone has gone home, then revealing that he has put Jim's "World's Best Boss" mug in jello as the theme song plays, reflecting the ending of the first episode.

Michael is a deeply, deeply repressed homosexual.
He's almost obsessed with the idea of having as many children as possible. In his mind, having children equates with heterosexuality, and if he has enough kids, it will make him straight. His overly sexist comments and childish fixation on the size of women's breasts is just compensation.
 * Exhibit A: in his journal diary, he notes how "hot" he thinks Ryan is.
 * Exhibit B: Every other scene Michael and Ryan share.
 * Because gay people never have children. It's also heavily implied that Michael wants kids because he doesn't want to be lonely. He could still be a closeted homosexual or bisexual, though.

The documentary was never meant to be aired.
It's a class project for a local college, and is never broadcast at all. The crews have been there for so long because (from the assigning teacher's point of view) they keep getting great material and (from the company's point of view) Michael sees it as giving back. The crew sometimes follows people (e.g., Pam to New York) for extra credit. This also explains why they never film in the summer.

In "Scott's Tots", Dwight put himself as third on the Employee of the Month results.
If Jim had kept any level of composure he might have selected the employee after himself and Pam, for which Dwight surely would have planned.

The camera crew hasn't actually been there since the end of Season 3, but the good people of Dunder-Mifflin think it is because they've gone insane.
This would explain why everyone seems so much more eccentric now.

Rolf is the Scranton Strangler.
Dwight's account of how he met his best friend Rolf is quite suspicious: Rolf was asking for shoes that would allow him to move faster without leaving footprints. Rolf himself is quite the creepy character and displays a deep hatred for women with questionable moral behavior, which could be a typical serial killer trait. Not to mention his over the top verbally violent outbursts. And it fits with Dwight's personality to have inadvertently befriended a serial killer. This will probably be addressed by a quick glance at a picture on a newspaper of Rolf having been caught and identified as the Scranton Strangler, and much later Dwight commenting on how he hasn't heard from Rolf in a while.
 * The "Costume Contest" ep says he's still on the loose.

The tapes aren't getting shown because they're blackmail.
When the documentary crew started, they intended to get honest footage of how a paper company works. Dunder Mifflin happily went along to get their name out there, paying the documentary crew to film at the Scranton branch. However, both the documentary creators and the executives realized the massive amount of lawsuits and bad PR they'd be swimming in if the tapes got released. Dunder Mifflin pays the documentary crew to never release the tapes, and the crew keeps on filming so they have more to blackmail with. Sabre picked up the deal where Dunder Mifflin went off.

The seventh season will be the final season
With Steve Carrel officially leaving after the upcoming season, it seems logical to end the series with Michael leaving for whatever reason. And since the show's not really up to steam as it has been, it might be for the best to end it there. Hopefully he'll leave with Holly and a "Where are they now" style epilogue will wrap up the series.
 * Apparently not, as B.J. Novak and others have signed contracts for an eighth season.

The camera crew does not exist...
...and is a product of David Brent's Walter Mitty-style attempts to compensate for the grey little failure that is his life. The vitriol he's subject to by other characters when he's not present is imagined by him as a manifestation of his self-loathing; he is in reality a moderately well-liked, if somewhat quiet and withdrawn, boss.

Creed is the Scranton Strangler.
Though that might be *too* obvious...

Aliens.
They are filmed by aliens.

There is no reality show and it's not a documentary.
The cast is just aware they're TV characters.

David Brent will be back
Since Carrel is going to leave the show, Michael Scott will either be fired or retire, and get a happy ending with Holly. Then Dunder Mifflin/Sabre will hire a new regional manager for the office, and that new regional manager will be David Brent. After all, Brent did asked Michael if Dunder Mifflin was hiring. They will be hiring, once Michael is gone. Okay, that's mostly wishful thinking. But it would be awesome, even if it would be planned to last only for one season, or a few episodes at the beginning of the 8th.
 * Almost, but not quite. Brent was indeed one of the candidates for Michael's job. However, he didn't get it.

Toby will transfer to Nashua to keep Holly at Scranton
Seems like this would be a thing to keep Holly and let Toby escape Michael. Maybe Michael would treat him as a friend after this?
 * Jossed. Both Holly and Michael left Dunder-Mifflin altogether. Though you probably know this already.

Alternately, Michael with either transfer to Nashua, or just quit and move there in order to be with Holly
It would be an easy way to write Michael out of the show.
 * Jossed. Both Holly and Michael left Dunder-Mifflin altogether. Though you probably know this already.

David Brent will replace Michael
They're still looking for a replacement and Ricky Gervais is slated to appear with a "larger role" in the season finale.
 * Almost, but not quite. Brent was indeed one of the candidates for Michael's job. However, he didn't get it.

Catherine Tate's character who was interviewed for the management position at the end of season 8 is Donna Noble.
She really does seem to act how Donna would have prior to meeting the Doctor, or more likely after, while trying to act like she's fit for a management position for which she is clearly unqualified. The timeline works out for her to have moved to America in search of an easier-to-get better job after her time as companion was over, possibly at Wilfred's suggestion.

Two different sentient species share the Earth of The Office
"The Cameras" are a second sentient species within the universe of The Office, they are human looking creatures who can record events exactly like a video camera does in our world. Their memories are flawless and can easily be converted from brain waves to video feed. They mostly work in the entertainment industry. Some people are more used to this creatures than others, when some characters seem to react more visibly to the presence of "the cameras", it actually means they are a variety of racist, or spesist that feels uncomfortable with these other species. Michael Scott, who thinks of himself as an entertainer, of course is the one that feels more comfortable with these "camera people". The main difference from our universe with that of The Office is that Reality Shows can last years, even entire generations, thanks to the fact that the "camera crew" is basically a single individual who is recording with his or her own eyes. In fact, the "camera people" may be a sub species of humans that are indistinguishable from us, which allows them to be present at events where actual camera crews could not be present, such as Michael's negotiations with Jan for a pay rise, Jan thought it was just a Dunder Miffling clerk, when it actually was one of the "camera people" who are working on The Office reality show, and had infiltrated Corporate to get juicier bits. As of the end of season 7, no "camera people" working on The Office reality show has infiltrated the Sabre Headquarters. People is mostly used to the notion that they can be being filmed at all times by the "camera people", and the notion of having to sign waivers to allow their image to be on film is non existent in The Office universe, that being the reason we never see people with blurred faces. The "camera people" may be required by law to reveal themselves as such when working, but they may not always do so, if it benefits the filming. Also, the "camera people" undergoes, since very young, a conditioning to actually see genitals and female nude breasts as pixelated patches, and to hear some swear words as beeping sounds. The Office reality show is of a format that is intended to be aired after some 10 to 15 years of material ha been recorded by "camera people", shows on that format are happening all over the place in that universe.

Jim and Pam will have another baby in season eight.
Jenna Fischer is pregnant in real life, so it'd make sense to write it in. There wouldn't have to be as much focus this time around, like with Cecelia. No camera crews in the hospital or anything like that. Confirmed by Jenna herself in this article: http://nymag.com/daily/entertainment/2011/07/the_offices_jenna_fischer_conf.html
 * Confirmed.

Angela's baby is Dwight's.

 * There's no way that Dwight/Angela's storyline is over, despite her marriage to the Senator. Calling it now!
 * Confirmed in "Jury Duty".
 * "Confirmed" means it's a definite fact backed up by evidence. It hasn't been confirmed, although it probably is his baby.

Creed Bratton isn't actually Creed Bratton. He's a psycho who murdered him and stole his identity.

 * "No one steals from Creed Bratton and gets away with it. The last man who did disappeared. His name? Creed Bratton."

Angela may face the threat of being fired
With the fact that, plus her behavior about   came off as very very prejudiced. Also I personally would like her ass canned.
 * If she was going to be fired over the Oscar situation it probably would have happened back then. I don't see her getting fired any time soon. She's pregnant. It's considered pretty lousy etiquette to fire a pregnant woman without an extremely good reason, and I don't think "gay husband" has ever been grounds for dismissal.
 * Also, she's head of the Accounting department, so despite her personal views, she obviously does good work. She and Oscar get along well enough, so there really isn't any reason why she would be fired.

Dwight treats Jim as he would treat a brother

 * Dwight actually sees Jim as a good friend, possibly his best friend, and treats him just as he would treat a brother. It's just the Schrute's have aggressive and antagonistic relationships with family.

Angela still has feelings for Andy

 * The cat she keeps at the office? It's the one Andy gave her.

Oscar's sexual harassment settlement included stock options

 * For what other conceivable reason would Oscar own Dunder Mifflin stock?

The show takes place in an Orwellian alternate universe

 * Everybody in this universe knows that they're being monitored, and everybody knows it's not for the purpose of obtaining dirt or criminal evidence against people so much as evaluating the results of The Party's social engineering programs. Everyone, that is, except Michael Scott, who believes the Secret Police when they tell him it's a reality show. Parks and Recreation also takes place in this universe.

Oscar clammed up on purpose at the shareholders meeting

 * His new ideas wouldn't have changed the character of the people who mismanaged it, and he'd gotten sick of his good ideas constantly being ignored. Add to that the fact that the company swept his sexual harassment claim under the rug, and the fact that he could probably find other opportunities if need be, then perhaps he just wanted to watch Dunder Mifflin go down in flames.

Shortly before the film crew arrived, their coworker Tom committed suicide.

 * In Performance Review, Michael read old suggestions from the suggestion box, including "We need better outreach for employees fighting depression" by someone named Tom. Phyllis reminds Michael that Tom shot himself.

The Grand Finale will feature Erin's wedding

 * Michael will be Back for the Finale to walk her down the aisle.