Diddy or Sean Combs or whatever was one of Letterman's guests last night and he shared an interesting story about a time when Michael Jackson showed up unannounced at one of his famed White Parties.

David Letterman, who has been quietly doing his second-place late night joker show over on CBS like forever, is all of a sudden beating the Tonight Show in the ratings. Calling Sarah Palin a slut really pays off!

While everyone is busy fretting and fussing over Conan O'Brien's freshman Tonight Show run, his steady-as-she-goes CBS competitor, David Letterman, has been quietly inking a deal to stay on the air through 2012. With, sigh, a bit of a pay-cut.

Conan O'Brien is set to debut as the new host of the Tonight Show this evening, which is exciting. Though we do worry that because he's now on an hour earlier, our favorite kinds of Late Night bits might be deemed too weird or risky. Favorites likes these hallowed treasures:

Oh, to write jokes for one of those late night TV shows! Seriously, please, let me do that. Those staff writers get paid. But the freelancers get totally screwed!

Jimmy Fallon was mercifully blessed to have former Saturday Night Live/Weekend Update co-star Tina Fey on his second show.

Sure, Jimmy Fallon was awkward on his Late Night debut, as first-time hosts tend to be. But expectations are so low the comedian just needed to show a little promise. That he did.

Jimmy Fallon's critics hate him for being so awkward and manic. But all indications are the Saturday Night Live veteran will embrace those qualities, crafting the geekiest Late Night yet.

News comes today that when Conan O'Brien starts hosting the Tonight Show from LA in June, his old Late Night sidekick will once again be along for the ride. As, sigh, the show's announcer.

Robert De Niro will be Jimmy Fallon's first guest—an unusually intimidating choice to ease first-night jitters, no matter how well their "Are you a pothead Fallon? Could you milk me?"-patter goes in rehearsal.

Conan O'Brien's story seems more bitter each time he's asked about learning Jay Leno would precede his Tonight Show on NBC.

Now that Late Night has worked YouTube's apoplectic Hong Kong flight misser into its skit lineup, other parodies and mashups can't be far behind. (Or at least SNL.) Clip after the jump.

Ideally it would have been great to see Jimmy Kimmel come out and cut Nightline's throat in his just-released interview with Broadcasting & Cable. But! There remain some jagged edges in his late-night diplomacy.

Somehow we knew Alec Baldwin would come for you first, Joaquin Phoenix. The actor seems as hostile to strung-out hippies as his 30 Rock alter ego Jack Donaghy.

David Letterman is reportedly in talks to extend his CBS contact beyond 2010. The idea is to take ratings from Conan O'Brien's Tonight Show; further taunting Jay Leno is a fringe benefit.

ABC might move Jimmy Kimmel Live to compete with Conan O'Brien's Tonight Show, the New York Times is reporting. ABC is pissed about the story. But it gives Kimmel reason to smile.

It's been a while since we checked in on Jimmy Fallons's Late Night rehearsal webisodes, so let's see what he's up to. He's... uh. He's... not doing much.

All eyes were on Conan last night in anticipation of what, if anything, he'd say about NBC's surprise announcement that Jay Leno would upstage his long-planned ascension to The Tonight Show throne.

You have to hand it to Jimmy Fallon: He dispensed with the inevitable topic of being called a "douchebag" on the internet (by this guy apparently) very quickly, in the second "webisode" for his forthcoming Late Night. You can totally see the joke coming, but at least he's trying this time! And he's tripled the runtime to four and a half minutes. Which is plenty. Seriously, it's fine. Really. Enough. (Video after the jump.)

Jay Leno will stay at NBC and move to 10pm weeknight slot after Conan O'Brien takes over his Tonight Show in June, Broadcasting & Cable and Nikki Finke are reporting. Everyone thought Leno was probably going to end up at ABC after he said in a July interview "I am definitely done next year - with NBC." But NBC Universal chief Jeff Zucker persuaded him to stay! Probably with wheelbarrows full of money. The big loser in all this? That would probably be embattled NBC Entertainment co-chairman Ben Silverman, who just survived a major corporate bloodletting but suddenly finds himself with five fewer hours a week to program. And to think he was having so much fun skiing in Utah this weekend!