I think writing Jon Stewart off as an SNL skit is pretty grossly inaccurate and shows a bit of a lack of understanding of what the Daily Show is and how it operates.
Yes, they run on Comedy Central. Yes, Jon Stewart is a comedian who uses humor and all of its subsidies such as wit and sarcasm to show the news. But to write it off as nothing more than a mindless skit with no purpose? More and more people are turning to TDS as a source of news and a way to supplement their political know-how because he has the creative freedom to point out the inaccuracies and hypocrisies of both sides from a fairly safe sideline and the means to do so in the avenue he knows best as a comedian -- comedy. He's reported on issues that sometimes "serious" news networks won't -- he was applauded later on for his involvement in the 9/11 responders case because he put a spotlight on an important issue that other networks didn't deem worthy and pointed out the glaring and disgusting hypocrisy of the GOP on the matter. Comedian though he is, it seriously begins to blur the lines between comedian and journalism because he walks the line very, very well.
It's not to say Jon Stewart is the paragon of absolute fairness -- it's no secret that he has a left lean and that his audience is largely liberal, but he has shown time and time again that he's willing to nail both sides on their stupidity when it comes around, which puts him miles and miles ahead of sources like Fox News or MSNBC. The Rally to Restore Sanity is a great example of Stewart reaching out to moderates who are turned off by the insanity of both sides of the fence.
Finally, Jon Stewart and Glenn Beck run shows that are nothing alike and to compare the two is laughable, at best. I only wish Glenn Beck's segment were nothing but satire in the way that Steven Colbert's is, but he's passing off his fringe lunacy as tangible fact in a way only Fox News could pull off -- blending opinion into fact to the point they're nearly indistinguishable. Even Jon Stewart consistently mocks his own show as not being very serious, his show peppered with obvious staged reporting despite the fact that when he needs to, he does report on very real issues. He at least attempts transparency and disclaimers that you should not take what he says as irrefutable truth. I'm not so sure that you can say the same thing for Beck.