Answered: Stephen Colbert to Replace David Letterman as Host of CBS' 'Late Show' - TheWrap

=== Old Answer ==
Jay Leno. He'll come back, take down Jimmy Fallon, and reclaim the Tonight show. Just kidding--his public response to David's retirement was no.

Craig Ferguson. If we take Ferguson's visits to David's show as a guest, he started off strong, but in the recent years, has flopped with David's audience. The turn was the October 2012 interview: prior to that, Craig was respectful and positive and energetic. Starting that interview, he started degrading humor, which doesn't work with David's audience who respects Craig's targets, David and Paul. Actually, David also changed his tone--from respectful, to degrading as well. INTERESTING: 2012, I think this was the first interview since Craig must have tried to take the Late Show from David Letterman, and David refused. Leno was already gone and the Tonight show had evolved, I'm sure CBS wanted to follow the suit as well. Furthermore, when Craig bantered with Paul, Paul accused Craig of not providing jobs because Craig has a single robot instead of a band--therefore employing less people than David does. This may stem from Paul's sensitivity about almost loosing his own job and for his band members. Since 2012, I don't think ferguson has gone on David's show.
The interview:

Jon Stewart. He'd have to change too much to fit CBS I think--his humor is always highly politically charged, and I don't know if CBS wants a show that has so much constant political overtone. He may be better where he is.

Stephen Colbert. Seems to be the top choice by CBS according to Mashable I think adapting his show to Late Night would be difficult, since he plays a character. However, given that The Tonight Show Starring Jimmy Fallon is now full of characters given the SNL style comedy, perhaps that's where the industry is moving. Perhaps that's why he's highly considered for the part. I think he would not have to change much about his character to adapt to CBS's audience because the category of humor that he uses, a vacillation between seriousness and absurdity, is very similar to David's comedy. The nature of the comedy is the same, just the delivery is different: one is through David himself, the other is through Stephen's alter-ego.

Neil Patrick Harris. Wasn't my guess, but the tabloids seem to be pushing for him, so I'll comment: my impression of him is a lot of singing and dancing routines. He might do very well as the band leader sidekick, less so as the calm and reserved host, which we typically expect (historically) a host to be. This is why Conan gets criticized so much for his over the top behavior physically--it is unbecoming of a respectable host. This may be a deal breaker since Neil's personality is an animated one. But Fallon is certainly more animated than Leno was, so perhaps that's where the industry is shifting.

Conan O'Brien. I don't think so. He's been burned once before, and from that experience, he's learned that he can't survive without a show--he spoke in an interview about how he felt restless after leaving The Tonight Show and just couldn't wait to get back in touch with performing for his fans. He is in a good place with TBS, he's the big fish in a small pond, free to do what he likes. He's happy where he is, there is no incentive: he doesn't need the money. The only thing to drive him to pursue the job would be his desire to prove himself, to prove NBC wrong in saying he wasn't good enough.

Jerry Seinfeld. He's a billionaire, he doesn't have to work, but he still shows up, and his newest show, Comedians in Cars Getting Coffee, is basically an interview segment. His prior stand-up work included brief sketches, which would translate well to a show. The risk is that he is a bit out of touch--his last appearance on Jimmy Fallon was a flop, drawing very few laughs, so he'll need to fix that to stand a chance.

Tina Fey. Funny as a host, unproven as an interviewer.

Ellen DeGeneres. Very clean humor, funny, but predominantly female viewership, at least evidenced by screen shots of the audience. For that sexist reason, probably not going to be considered.

Ray William Johnson, Tosh.0, or other Youtube stars could be underdogs, but only of the above top tier turn down the job.

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