Yes it is. Bear in mind today’s date, but this has apparently been confirmed by multiple sources: Smith and Tennant and Billie Piper (<—DO NOT CARE) will be in the 50th anniversary “Doctor Who” special. Question, though: doesn’t the doctor only have 13 regenerations? Aren’t we getting dangerously close to that number? From Wikipedia:
The John Peel-authored book The Gallifrey Chronicles attributes regeneration to a “nanomolecular virus” that rebuilds the body. The audio play Zagreus attributes regeneration to “self-replicating biogenic molecules” designed by Rassilon, which do much the same thing, with a built-in limit of twelve regenerations to prevent the molecules’ decay. According to the Virgin Missing Adventures book The Crystal Bucephalus by Craig Hinton, Time Lords have triple-helix DNA: the third strand was added by Rassilon to make regeneration possible. These varying explanations may or may not be compatible with each other, and like all spin-off media, their canonicity with respect to the television series is unclear.
Rumors that Matt Smith may move on (which, by the way, Smith has smacked down) seem scarier because of this.