In the recent published The Brilliant Book of Doctor Who 2012, Steven Moffat has hinted at the 50th anniversary in 2013.
"Epic, huge, massive, indulgent... all your treats at once. The BBC is committed to the 50th anniversary, everyone is committed to it... and I guarantee you it's going to be the best year ever to be a Doctor Who fan. We're going to be in production for longer than ever, just to do everything that we intend to do".