Hmmm...

Doctor Who: BBC responds to Matt Smith quitting rumours

The BBC was quick to respond to the story, and had this to say:

“Sorry folks but even we don’t know what’s going to happen at Christmas. It’s not been written yet! But Matt loves the show and is to start filming the unmissable 50th anniversary, and the new series starting on Easter Saturday.”

It's not exactly a denial, and neither was Smith's answer to the question posed by Jonathan Ross last week, "I am very happy doing it. I do the anniversary special, then the Christmas special. At the moment it’s 2013 and we will see what 2014 holds.”

Sounds like things either haven't been negtotiated quite yet, or they're being quite mum about post-2013. I won't despair quite yet. Only two more regenerations per 'Doctor Who' canon, although I'm sure they can find some way to extend it without stooping to the Master's evil. But it's a pretty firm rule in the minds of the fans, as pointed out in the Wikipedia article, so I'm not sure what they'll do. Any way, at least two left, although I'm rather fond of Matt Smith. I think he brings a great amount of energy to the part.