I think he's bluffing. Arizona is too good a situation, especially for a QB who knows that it can take one bad fit to sidetrack your career. Kerry Collins re-signed early and for a lot less than people expected, and I think it set a precedent for veteran QB's that Warner's now trying to escape. This feels like a ploy to get the Cards to come to the negotiating table more desperately.
Going to a division rival, haha. If he signs with San Francisco, he could be a good mentor for the younger quarterbacks. I don't know how high the chances are though of him signing.
It's a ploy to build leverage I'm sure....the question is: How far will they take it? If hes not prepared to actually sign with them and the Cards know, it creates nothing....