Apparently Matt Smith has been announced as the 11th Doctor when Tennant leaves.

I didn't really like the Christmas episode. I think Davies had a great run up until Last of the Time Lords. Nearly everything after that (save the Moffett Library story and Midnight) have been so-so. I really enjoyed the Next Doctor up until they revealed he wasn't actually a future Doctor. It was such a cop-out and a terrible tease. I thought it was brilliant when it seemed Tennant would have a traumatic regeneration leaving a flawed Doctor. I was hoping they'd have the 11th Doctor say that in his confused state he went back in time a few months to prevent the terrible regeneration, then at the end he saves Tennant and ceases to exist. That would've been a good way to go, but to have him just be some guy was terribly lame. And the cheesy applause scene made me feel both angry and ill. The only thing I liked was that they showed all 10 Doctors on the infostamp, but that was about a minute out of an hour.
It really could've been epic if someone with balls had been running the show. Davies oerstayed his welcome and I'll be looking forward to Moffett taking over.

Bow ties are coool.