Where's Sarah Palin when you need her? The fourth-season premiere of NBC's Emmy-winning "30 Rock" was down a steep 27% in the adult demo from last fall, when star Tina Fey was generating national buzz for her "Saturday Night Live" parody of the Republican veep candidate. "30 Rock" returned to 6.3 million viewers and a 3.0 rating among adults 18-49, falling 25% from its "Office" lead-in. Meanwhile, ABC's "FlashForward" (9.1 million, 3.1) stopped its ratings descent, reversing for the first time to climb a tenth of a point. ABC just picked up the drama for a full season, so this...