The Amanda Show/WMG

Penelope Taynt is Amanda's long lost twin.
She's not really just a crazy fan, she's Amanda's long lost twin and that's why she obsesses over finally getting to meet her, so she can finally collect some DNA to tell if they really are related.

Amanada is part of Izanami's experiment
Note how she enters the TV in the original opening.

Moody's Point having no ending was planned
...so it would be a true parody of bad dramas/soaps it ended with a, completly planned, twist.

Amber from The Girl's Room isn't popular at all.
Her whole 'popularity' schtick is just a ruse to hide the fact that no one likes her. In fact, she probably so into the facade that she's completely lost touch with reality and is dangerously insane.

Debbie from The Girl's Room is a pothead.
How better to explain her spaced-out expression, nonsensical remarks, and constant cravings for eggs (the munchies)?
 * She fell in love with Kyle from Totally Kyle in one sketch. That's proof enough for me.

The people from Blockblister closed their store to direct the Twilight series.
Y'know, after giving Stephanie Meyer the idea to write it in the first place.

Amanda has chronic Multiple Personality Disorder and Penelope is just one of her alter egos.
It would explain why she has never met Amanda, yet knows so, so much about her.
 * It might be an explanation as to why they never met, but have you ever talked to a fangirl? They can be pretty obsessive and routinely know or remember things about a celebrity that the celebrity himself/herself and his/her friends and family might not.