I dunno about CNN International, but he was being considered a late night TV show on ABC's to compete with Leno and Letterman. They ended up going with Jimmy Kimmel - oh well. Too much of his humor could be over the edge for network TV.
Anyway, the Daily Show has had a lot of serior political guests. Including Al Gore! 😛 It's surprising that they get these people after making fun of them so much, but they do and often the interview is more meaningful and interesting than on CNN or a real news show.