Above: Bernard Cribbins as Tom Campbell, in a photo from the movie DALEK INVASION OF EARTH (1966). He would return to DOCTOR WHO in 2007 as Wildred Mott, Donna Noble's grandpa. More about recurring WHO actors in The Ones Who Came Back.
Ooh. Some good video in the run up to the final episodes.
Some rather mild spoilers in these clips, but if you have to get some DOCTOR WHO clips (and I have to) ASAP, then here they are. No major plot elements are exposed, other than stuff you may have seen in previous preview (like who the adversary is, what characters return, etc.).
New "End of Time" trailer:
A clip from the episode:
Bernard Cribbins & David Tennant:
In the United States, the final 3 Tennant episodes air on BBC America:
"The Waters of Mars" Dec 19
"End of Time" Part 1 Dec 26
"End of Time" Part 2 Jan 2
Hat tip to TrekMovie for the clips.