Looks like we’re going to get a bit more Tennant after all.
His last three specials are set to air in November and then around Christmastime (a two-parter which will see him regenerate into the 11th Doctor), but before those come around we’re going to get some more:
The Doctor will appear in a two-part episode of The Sarah Jane Adventures, which will air before the next special.
Plus, the BBC have announced another animated webseries featuring The Doctor, called “Dreamland”, which will also debut in Autumn (and most likely end up on DVD, just like the previous one, “The Infinite Quest”).
…and of course, there are still the persistent rumors of a big-screen movie… the BBC have admitted that a script is in development, but of course that means that any film is probably years away, which means someone other than Tennant in the role. (and if they keep to film tradition, someone completely different than any TV-screen Doctor)