Last time I saw Bush attempt to actually answer something resembling a hard question was when he was on Meet the Press with Tim Russert. He was evasive, stuttering, and would go off on tangent after tangent; not to mention that he always managed to end up harping on the same point while providing "answers" to several different questions.
Kerry needs to make sure he is clear and concise and makes Bush look like the idiot that he looks like when he's interviewed, stay off the personal attacks, and if Bush does start slinging mud then Kerryshould simply say that he will not respond to any personal attacks.
I'll keep my fingers crossed.