'Saturday Night Live' cast gets sketchier at an awkward time Over almost four decades, "Saturday Night Live"has displayed a Madonna-like gift for reinvention, defying critics who, every five years or so, question the show's relevance in a rapidly changing culture. The likes of Chevy Chase, Will Ferrell and Amy Poehler have come and gone, but "SNL" has endured. This year, "SNL" faces one of the most significant talent exoduses in its history - perennial stars Kristen Wiig and Andy Samberg are moving on, Jason Sudeikis is likely to follow, and after 11 years head writer and "Weekend Update" anchor Seth Meyers appears ready for another challenge - though he's denying rumors he's replacing Regis Philbin at"Live! With Kelly. Collectively, these exits could be the greatest challenge the comedy institution has tackled since the high-profile departures of Phil Hartman, Adam Sandler and Mike Myers in the mid-1990s. Growing pains are certainly nothing new for "SNL" or its creator, Lorne Michaels, but this latest changing of the guard comes at a particularly awkward time: NBC, which has languished near the bottom of the network ratings since 2004, has more than enough problems without worrying about the status of "SNL." " 'SNL' has to perform at a certain level," says Brian Steinberg, television editor at Advertising Age. NBC can't afford to have any cracks in the pillar. Both Michaels and NBC Entertainment Chairman Robert Greenblatt declined to comment. According to NBC spokesman Tom Bierbaum, the show has continued to hold its own. "SNL" ratings have held steady at an average of 7 million viewers since 2004, except during the abbreviated 2007-08 season. This year, the show averaged about 7.1 million viewers, down just a hair from 7.2 million last season. To put these numbers in perspective, that's as many as watch "The Biggest Loser," and double the usual audience for "The Tonight Show With Jay Leno." Not bad for a show that's about to turn 37. "SNL" also performs well among the coveted 18-49 demographic - especially when compared to the geriatric hinterland that is Saturday night television - and in particular young males. This is a draw for deep-pocketed advertisers, like beer companies and film studios, Steinberg says. Still, with a large ensemble cast, an even bigger crew, and wardrobe and costume expenditures that would make J.Lo blanch, "SNL" is by no means a low-budget production. According to a source close to the show, it costs NBC about $3 million to make a single episode, a budget comparable to that of an hourlong network drama. Though it's highly unlikely "SNL" would lower the boom on the show while Michaels is still involved, budget cuts are not unprecedented. In 2006, Michaels axed five cast members under pressure from the network to cut costs. Whatever the investment, it's worth it, according to TV analyst Shari Anne Brill: "There are people who came into 'SNL' who don't watch anything else on NBC. They need to remind people that they have shows on the rest of the week between 8 and 11. James Andrew Miller, co-author of "Live From New York: An Uncensored History of Saturday Night Live," acknowledges the show is at a crossroads. In particular, he calls Wiig's farewell "one of the most emotional departures in the history of the show." He cites her ability to portray a wide range of characters - not just the wacky ones, like Target Lady. There are dozens of performers who were great. They couldn't pick up the show and carry it on their back the way she did," Miller says. Her departure is not to be taken lightly. But others see a silver lining in the cast changes. "There was some fatigue with Kristen Wiig's characters," argues Adam Frucci, editor of the comedy website Splitsider. The same people who are saying the show can't survive without her were complaining about the Target Lady having her 15th sketch. Ryan McGee, a critic who writes about "SNL" for HitFix.com, agrees. "There's a really good chance for the show to blossom if they can give more screen time to other women, like Vanessa Bayer and Nasim Pedrad," two talented but underutilized performers. Likewise, Sudeikis' absence could mean more air time for Taran Killam, who's widely viewed as the show's next breakout star. In the past, big cast departures have cleared the way for new talents to emerge - think of Will Ferrell, who joined the show at a low point in 1995. The show's two-tiered cast also works as a kind of extended audition: Most new cast members start out as featured players and are upgraded to repertory status once they've proved themselves. It doesn't always work out, of course, but the bottom rung of the "SNL" cast has proved to be a creative staging area for major stars, including Jimmy Fallon, Eddie Murphy and Poehler, as well as Wiig, Sudeikis and Samberg. This is what Lorne does: He replaces people, he develops talent. It speaks more to his genius than just having the same cast come back year after year," Miller says. There's a part of him that likes proving people wrong. How many times have we heard 'Dead from New York'? It's the stupidest joke in television. There could be a nuclear war, the cockroaches would be walking around and 'SNL' would still be on the air. Miller also claims the show's ratings from week to week have more to do with the musical guest and host than with the quality of the individual sketches. The evidence bears out his thesis: This season's second most-watched episode, hosted by embattled starlet Lindsay Lohan, was also one of its most poorly received. If "SNL" is missing anyone this fall, it's likely to be Sarah Palin. Its ratings tend to peak in election years - viewership hit a recent high of 7.6 million in 2008, thanks to the gaffe-prone governor - but this election cycle offers two candidates who are unusually impervious to mockery. Fred Armisen's take on President Obama, while technically proficient, has never reached the transcendent levels of past presidential impersonations, like Phil Hartman's burger-scarfing Bill Clinton or Will Ferrell's haplessGeorge W. Bush, and without Sudeikis the show would have to find a new Romney. The stakes are high, says Miller: "If they do a presidential sketch on 'SNL' in September or October, and it's not talked about on Sunday or Monday, then that's a form of disappointment that they don't want to experience." These days, "SNL" also has to grapple with unprecedented competition. In the past, "SNL" has easily beaten the few shows foolish enough to go head to head in the same time slot, like "MADtv" and "The Howard Stern Radio Show." But"The Daily Show"and"The Colbert Report"have stolen some of their thunder when it comes to political satire. Meanwhile, young Web natives turn to sites like Funny or Die and College Humor anytime they're craving laughs, rather than parking in front of the TV on Saturday night. After a rocky start, "SNL" has adjusted admirably to the digital era. In late 2005, "Lazy Sunday," a micro-budget video in which Samberg and costar Chris Parnell rap aggressively about their banal weekend plans, became an unexpected viral sensation. The technophobes at NBC yanked the bootleg copies that had been posted to YouTube, but eventually they realized the value of making content available online. Now "SNL" is a show that's shared via email and Facebook by millions of people who haven't stayed up late to watch it in years - or don't even own a television. Yet even with the rise of digital media, the power of network airwaves should not be underestimated. Steinberg puts it bluntly: " 'SNL' has a broadcast megaphone that Funny or Die does not have. To have an audience of several million people is a big generator of buzz in a way that viral still isn't. The show also continues to carry a certain cachet, both inside and outside the comedy world: It means something to be a part of it.  'SNL' is still being courted, it's still a big deal for the candidates to go on, and it's still a big blip on the cultural radar," Miller says. In a way, the transitional year ahead is but a symptom of the show's continued success. "SNL" is a bit like an ouroboros that swallows its own tail - or put another way, it turns stand-ups into movie stars.