For the most part I would call it a tie.
Kerry did have a stronger finishing, the way he wrapped it up and the end was nice. But definitely not the strong showing that he had in the 1st and 2nd debate.
Kerry stumbled, and you kept hearing the same rhetoric over and over. You could see him slipping into his mass. accent with Idear.
Bush much better with his speaking, made some slip ups like the 75% figures on al-qaeda, the statement that Pikko quoted on Osama, the whole litmus thing, but for the most part pretty solid.
So I agree with Joph.