Matt Smith has teased that the 50th Anniversary in 2013 will be an "event".

Speaking to SFX he said:
"I think we've got to do something that is an event. We've got to create an event, absolutely. That's certainly the plan. I don't know what that is. The powers that be upstairs will decide that. But I'm hoping we can definitely make it something unique."
He also backed up his recent claims that he wants a multi-Doctor story for the anniversary, saying:
"That's what [an anniversary] is about. It's about creating an event for everyone who's been involved with Who, the fans included, and just going, 'Hey, look at this thing we've all been following for 50 years'."
With 2013 still 2 years away, there is a lot of talk around the anniversary at the moment!