I'm not convinced it will be close at all.
Obama is not in good shape to be in a dead heat at this point. CBS poll has them each at 42%. He was the novelty, not McCain -but no novelty any longer. People are already looking beyond the historic nature of his nomination and taking a harder look at substance now. But with no relevant experience, no major accomplishments in any elected office, his celebrity status wearing thin, people believing they have been over-exposed to him and hearing him dragging out the same old tired Democrat policies of more taxes, big government and big spending, already seen by the largest audience he's going to get at one time -what's left? He got his convention bump and immediately bled it off. Everyone has been seeing and hearing this guy from so early on and for so long now -if he wasn't able to draw them in before this point, what's he got left to attract them now?
Since he's shot his wad and can only keep on repeating what everyone has already heard ad nauseum and McCain's campaign got a new kick, I think Obama is likely to continue losing support over the next 2 months. I also think that a significant majority of the "undecideds" in these polls (which is a significant percentage of people) aren't going to go for Obama if they hadn't already been convinced by now. Unless McCain/Palin make a major and unforgivable blunder of course.