Well, Bush actually showed up to the debate tonight. He was able to use his swagger to his advantage, instead of coming off as someone entirely unprepared. He seemed to know where he wanted to go, without saying the same thing over and over.
But Kerry did well tonight, too, still much quicker with his responses. Bush needs to say, "Remember the last debate?" and try to pick up on some point that Kerry made there, because he was not able to refute Kerry's point at that time. Kerry, on the other hand, is ready for the on-point response.
One trend in Bush's responses tonight, made him sound like Han Solo in the very first Star Wars movie: "it's not my fault." Whether he was claiming that the errors in judgment about Iraq came from the generals giving him advice about troop numbers, or whether he was blaming the recession on previous administrations, or saying that his only mistakes were in political appointments, he never took responsibility himself. Sure, it's nice, in the best of all possible words, to have an infallible leader, but Bush is not that--who (in our real world) is? And given that, he would be a more credible leader if he took responsibility for his own choices, decisions, actions.