Here's an article from the NYT. In it he says he won't run if he doesn't think he can win, that he doesn't want to be a spoiler (ala' Perot) for the Democratic candidate. Interesting that he's been planning this for a couple of years. If he does run, he will take votes from Hillary. Link to Full Article
He's covered all the bases now from democrat to republican to independent. He's highly regarded as mayor of NYC; in fact some prefer him to Giuliani.