Media Guardian reports - "David Tennant Quits Who after specials"
source here - http://www.guardian.co.uk/media/2008/oct/29/doctorwho-bbc
David Tennant has announced that he is vacating the Tardis and leaving the BBC's Doctor Who series at the end of next year.
Tennant's decision brings to an end his popular four-year tenure as the time lord.
The BBC confirmed that the Scottish actor will complete the filming of four special episodes to be screened this year and in early 2010, as well as 2009's Christmas special.
More details soon ...
EDITED TO ADD - okay, the link has gone, but the text is what was there....My guess is, that this will be officially announced at midnight (as most DW news stories have been), and it was published by mistake. Let's see what happens at midnight
EDIT 2 - And David has Just confirmed this live, at the National Television Awards
EDIT 3 - And now being reported on BBC News -http://news.bbc.co.uk/1/hi/entertainment/7698539.stm