In the latest issue of Radio Times, out now with a special Planet of the Dead cover, David Tennant has spoken about the times ahead as the 10th Doctor's life comes to an end.
“You can sense the bell tolling for the Tenth Doctor. Something happens in (Special No.2) that fundamentally alters who the Doctor is and where he is, which is the sort of thing you can only do when you know that you’re coming to an end. That’s very exciting, and quite sad. The end is nigh. You can sense the Grim Reaper knocking on the door. But how many times?”
Oh no! Maybe he could change his mind and stay...? There's still time yet!! Thanks to WhovianNet for the news!