The remaining “Doctor Who” eps starring David Tennant as the Doctor as coming to a close in step with the season finale. First, “Waters of Mars”, airs on December 19th 9/8 C. “The End of Time” is the two part season finale and are the last eps of the David Tennant Doctor.
Executive producer, Russell T. Davies cues to the season finale:
“[Since the Doctor is warned that] the end of time is approaching, he’s much more concerned with saving the world. It never gets too dark. It’s got great jokes, and lots of chases and explosions.”
“The End of Time” will also include The Master played by John Simm, Donna Noble played by Catherine Tate, Donna’s grandfather played by Bernard Cribbins, and guest star Timothy Dalton as “The Narrator”. In the promo pic at the head and foot of this article, you can see Tennant’s Doctor with Donna’s grandfather!
The first part of “End of Time” will air on December 26th 9/8 C. No confirmation yet on when the second part of the season finale will air.
Take a sneak peek at “End of Time”:
In 2010, the next season of will see a new Doctor, played by 27-year-old Matt Smith.
[Source] TV Guide, Den of Geek