A couple of months ago we told you about the possibility that Mad Men's Jon Hamm would be joining 30 Rock as a love interest for Tina Fey. At first it sounded like one of those Hollywood casting rumors that's promoted just because it's about two hot shows. A lot of people thought that it probably wouldn't happen for one reason or another. But now it's official: Hamm is coming to the show.

And this isn't one of those one-shot deals. Hamm will actually be on the show for at least three episodes and maybe more. He'll play a doctor who lives in Liz Lemon's building and the two start dating. Hamm says that he has already filmed a couple of episodes.

This is gonna be good. It will give some good cross-promotion to two critically-loved shows. And we all know that Hamm can do comedy, based on his recent hosting gig on Saturday Night Live.

Mad Men has been taking over NBC Thursdays. First we had Rich Sommer on The Office and now this.