It's a dumb issue, really. If Kerry does swing wildly to the left and come out for a new ban, we're looking at a repeat of 2000, and I don't think even his staff is stupid enough to let that happen (although I might be wrong; they haven't covered themselves with glory so far). If Bush does come right out and state that he'll veto it if it gets to him he risks alienating the urban on-the-fencers and gaining no votes that won't already come his way when the AWB dies quietly less than a month from now.
It's the anti-gun fanatics who are beating the drums, trying to get their pet issue some prominence that it would not otherwise deserve. I think they'll fail - it's just not an issue either guy wants to touch, and for good reason.
Opening his big yap on the issue shouldn't be neccessary, his voting record, and bill sponserhip record (such as it is) speak for themselves. He'll ban any gun, anytime he can get away with it. He'll pack the Courts with like minded folks (which won't be hard since anyone he'd consider would probably already be "living document" type) and then steer a case or two to them to get the second amendment declared a "right" of the federally funded National Guard" once and for all. (But see my tag line)