The BBC have released a brief clip from next week's Doctor Who Christmas special, "The Time of the Doctor". It's a light-hearted moment involving the Doctor, Clara, and a turkey.
A couple days ago, BBC America released a longer trailer for the episode as well. This contains a bit more of what actually happens in the episode compared to the short trailer released by the BBC previously.
Update: And there's another one! Well, sort of. It's very brief. Just a familiar glimpse really.