Dean won't seek presidency in 2008 if he gets chairmanship
At least that is how The Baltimore Sun is reporting it (link):
Following a speech at George Washington University, the former governor said that if he became party chairman, it would preclude another presidential try, at least in 2008.
It's actually not an absolute statement that he won't run in 2008. It's more an acknowledgement of the reality that holding the DNC chair would make it difficult for him doing so.
Of course, if Dean were in charge of a profound turn-around in party fortunes in 2006 then whose to say whether the party might not be more open to the possibility of his running anyway.
Here's how the AP reports it (link):
One woman among the crowd of well-wishers who surrounded Dean after the speech asked how she can contact him, and Dean told her that if the DNC "works out," she could contact him at the party. Dean also told reporters that anyone who becomes DNC chairman should be ruled out as a candidate for president in 2008.