NBC Renews "30 Rock" and "The Office"

Liz Lemon fanatics and Michael Scott superfans rejoice. They're both coming back in the fall!

The Associated Press reports that NBC has renewed the comedies for the 2009-10 season. Weight loss competition The Biggest Loser also got a pickup.

Amy Poehler's new sitcom, which will be a mockumentary about local government, will premiere at 8:30 p.m. EST on Apr. 9. The show has no title yet.

As for ER, which is in its 15th and final season, there are three more episodes that will air before the show ends with a two-hour finale on Apr. 2.

Angela Bromstad, NBC's new president of prime-time entertainment, said the fate of other shows is still up in the air.

Heroes is secure, she said. And as for a reason as to why it's been slipping in the ratings, she said it "may have taken on too much in terms of characters and multiple story lines."

NBC feels "very strongly" about shows Friday Night Lights, Life, and Lipstick Jungle. The latter is not cancelled, Bromstad said, squashing that rumor.

Shows like Knight Rider and Kath & Kim aren't doing so well and Bromstad admits the shows were "fair tries." She said they are "indicative of shows that may or may not be coming back."

Stay tuned.