30 Rock is back tonight — you may not have noticed. Like most of the show's viewers, we're excited for the return of Tina Fey's ensemble comedy, but the deathwatch will be on in full force after tonight. NBC's continued emphasis on stunt casting (Oprah! Steve Martin! Jennifer Aniston!) already reeks of desperation. We're skeptical a not-so-famous guest star in every episode is going to broaden the show's appeal any more than Liz Lemon's quest for a child will. Is the best comedy on television destined to be ruined in its quest for ratings?The early reviews are already in, with mindless Times TV critic Alessandra Stanley bizarrely noting the show's "satire hews so closely to the original that it is almost mimicry" as part of her "rave." WaPo critic Tom Shales is particularly high on next week's Oprah episode. Though Shales notes that he prefers Fey's Palin to the dour Liz Lemon character, both think Fey's popular Palin impression will give 30 Rock a boost. We want to believe, but we have our doubts. From its inception Tina Fey's show was destined to be a niche comedy that attracted SNL fans who enjoyed the insider-y view of NBC. For this third season, the network's promotional efforts have amped up. NBC is banking on the idea that Fey's Palin portrayal on a few highly rated SNLs and exposure in a modest hit film with a similar plotline in Baby Mama have given the show the exposure it needs to succeed in the high-profile post-Office timeslot. Given that the stunt casting for this episode is Will & Grace shrillster Megan Mullally, we have to question this approach. It's hard to see how featuring Oprah as herself is going to create buzz for the show — Oprah's viewership doesn't care if she's on a comedy show about the backstage life of a comedy show past whatever episode she's on. Comedians Jerry Seinfeld and Al Gore didn't improve viewership, and a slighter higher caliber of stunt casting won't help matters. The ongoing storyline this season will find Liz Lemon bringing a new baby boy or girl into her busy life, and it's a perplexing creative move. Artistically this didn't work out so great in the horrific Baby Mama, so consider us skeptical that it will add more viewers. And while Fey's Palin impersonation on Saturday Night Live was popular, it may not have won her friends in half the country. That's not the say the show should have just stuck to what it was doing and hoped the audience caught on. Fox's Arrested Development died waiting for that to happen. In the end, NBC's best way to make 30 Rock a hot ratings property may be through new media, not old. Making viewer-friendly decisions like making the premiere available on the web before tonight was a savvy move, and the show should punt DVD sales for awhile and promote its free presence on the popular Hulu service. We can't think of better advertising for 30 Rock than the show itself.