We used to worry about the separation of church and state (news and advertising). We used to worry about the blurring of opinion and news.
Now we have the blurring of comedy, parody, and news, and lots of people hanging around Washington DC when they should be watching the Georgia-Florida game. The Stewart/Colbert thing will no doubt be funny, will get covered by cable news, and will get far more attention that it probably deserves. But what the hell. These guys are damn funny, almost as funny as some of the candidates running for office (such as my congressional district).