Who will replace David Letterman? Let the errant speculation begin!

We know David Letterman is irreplaceable. But who will replace David Letterman?

There are many names, few truly qualified. Which means you must immediately rule out the superficially appealing names because they will never happen.

These include people like Jerry Seinfeld or Neil Patrick Harris or someone I'm not thinking of at the moment (Pee Wee Herman, Bruce Jenner .?.?.) They have never hosted a late-night talk show, and I am mindful of many stories of late night past: Stars like Billy Crystal (who had the sense not to do one for Fox) and Chevy Chase (who did not have the sense to do a show for Fox) believing that this gig must be a cinch.

("Hey, you show up, tell a few jokes, talk to some guest, then say goodnight .?..?") 

This is the hardest job in show business, by far. It's every day, weekends off. It's grueling work where you manage huge staffs, spar with networks -- the worst part of the job -- and then stand out there every night and try to be funny.  It's lucrative, but I can't imagine Jay Leno or Letterman did this for the money, which was ridiculously good, as they would be the first to admit.

 So who does this leave?

 To a list.  

 Stephen Colbert: Front-runner, without question. His contract at Comedy Central ends this year, CBS is interested (I have heard this from a senior industry executive) and he is very good and very funny. Questions, no doubt, about whether he will "break character." Should be a cinch. Plus, he's an excellent interviewer.

Jay Leno: Jay's name has to come up here. He's one of the most successful late-night talk show hosts in history, and he's unemployed. Why shouldn't it come up? One possible reason: His "Tonight" attracted an "old" audience (pushing 60, on average, which is old, I guess.) TV covets youth.

Chelsea Handler: The dark horse candidate and the long-shot candidate. She's leaving E!, she's funny, she has a following, and she knows how to do late-night TV. Drawback: She's a she. Late-night TV hosts are usually men. Don't blame me -- I don't make up the rules. Plus, she's leaving E!. I mean really .?.?. "Former E! host replaces Letterman." Rather sad headline, wouldn't you say?

Jon Stewart: Of course everyone wants Jon Stewart -- but could some watered-down approximation of "The Daily Show" work at "Late Show?" Hard to believe, possibly harder to stomach. Stewart is -- I don't use this word lightly -- a genius at what he does. He would be miserable to the point of throwing-himself-in-front-of-oncoming traffic to chat with the latest star selling the latest lousy movie. But who knows what's going to happen? He's certainly smart enough to figure out some sort of inventive way to reshape "Late Show." I still say: Long shot.

Craig Ferguson: The in-house star and a long-shot. Ferguson is excellent, funny, inventive, interesting, and has a terrific animatronic sidekick in Geoff. But "Late Late Show" always lost to Jimmy Fallon's "Late Night." How would a Ferguson "Late Show" then do opposite Fallon's "Tonight?" (Again, I don't make up the rules.)