Is it time to start worrying about 30 Rock? Consider this: NBC has already pushed next year's premiere back to midseason, ostensibly to accommodate Tina Fey's pregnancy. And Alec Baldwin has been adamant that he'll leave the show when he contract is up in 2012, and that Fey is planning to do the same.

Co-showrunner Robert Carlock denies he and Fey have made a decision about whether next year will be the show's last, but that might not be their choice to make. Fey's contract also expires next May. Meanwhile, NBC has taken to  pushing its new fall lineup in ads on trade sites like TV by the Numbers with the promo tagline, "It's a whole new NBC!"

Will the "new" NBC be as inclined to keep the critically-acclaimed, ratings-challenged show on the air without its most compelling character?

When the subject of keeping Baldwin came up in the extended transcript of Carlock's interview with New York magazine for this week's cover story on showrunners, it was clear the thought of life without Alec left him unsettled. "You'll have to ask NBC what they’re prepared to do to make them change his mind [about leaving.]" said Carlock. "And we’ll do whatever what we can do to make him change his mind and keep writing him that character. ... Obviously Alec is a huge part of making it good. Hopefully we can make it all happen."

Then again, would the "new" NBC break the bank on new deals for the stars of a show that's never been higher than 69th in the ratings? As Entertainment Weekly's Ken Tucker points out, much of the "new" NBC's fall lineup brings back memories of the "old" NBC's fall lineup. "'Quality programming' and 'two hours of The Biggest Loser' are not compatible phrases," states Tucker, not unreasonably. So why does the new schedule include--wait for it--two hours of The Biggest Loser on Tuesday? Because new NBC head of programming Robert Greenblatt, brought in from Showtime in November after the Comcast merger, deemed it "stable and working." He's probably right. But if The Biggest Loser is "working"--which is to say, consistently registering ratings in the top-20--30 Rock is not.

Also of concern for fans: Greenblatt's the same executive the New York Post reported in January wanted to  "push the envelope as far as his new bosses will let him" in bringing "racier" fare to the network. 30 Rock is many things--funny, savvy, occasionally nonsensical--but racy is not one of them.