A little late but Letterman finally aired the Bill Hicks bit that he censored in '93 (link). I thought he was very gracious about it, having Bill's mother on and accepting full responsibility for having removed the segment. Dave isn't very funny anymore, but at least he's getting a bit of a subversive edge back; consider the way in which he pilloried McCain when McCain "stopped campaigning"; nobody else on TV would have done that kind of stuff.
When I lived in Austin, I got to know of Bill Hicks because I watched a lot of public access TV. For some reason the public access content is much more interesting (and raw) in Austin than I've seen it anywhere else. However, I only recently watched, thanks to youtube, the Austin Public Access video in which Bill discusses the Letterman censorship incident at length: link.