I'm hosting some friends coming from out of town for it, so I'll be there (though I'm more into Colbert) but probably can't meet up.
Terry Gross had an interview with Stewart that went some way to explain their differences -- in doing the Daily Show Stewart became less interested in politics (as he describes it), but Colbert discovered his:
http://www.npr.org/templates/story/story.php?storyId=130704771
-- Andy