Well this is stupid...

He travels through time and space, saves the Earth, and has millions of fans all over the world. But as every "Whovian" knows, the Doctor cannot last for ever: Time Lords are able to regenerate only 12 times before they die.

Fans have always thought that the 13th doctor would be the last, thanks to a 1976 Doctor Who episode, The Deadly Assassin, featuring Tom Baker as the Doctor in his fourth incarnation, and revealing for the first time the regeneration limit. But a passing comment in a children's television programme later this month is set to rewrite history and cast the Doctor, iconic hero of the world's most successful and longest-running science fiction series, as immortal.

The moment comes in the CBBC spin-off show, The Sarah Jane Adventures, which stars former companion Elisabeth Sladen as Sarah Jane Smith. Matt Smith, who plays the current Doctor Who, guest stars in a two-part episode called The Death of the Doctor, to be screened on October 25 and 26. While the Doctor and Clyde Langer, played by Daniel Anthony, are in the process of outwitting spooky vulture undertakers the Shansheeth, Clyde asks how many times he can regenerate. The Doctor indicates that there is no limit.

Full story: http://www.guardian.co.uk/tv-and-rad...al-reveals-bbc
The story lines of The Master have already given them more than one way out to "reset the clock" on the doctor's regen limits without messing with established lore. Why they would they simply choose to ignore the limit? I have to say the longer the current production team is in charge of The Doctor the worse the franchise will probably get