It’s possible. McCain vs. Obama certainly widens the playing field for both parties. My concern is that McCain won’t have enough money to really campaign in California and he might have to spend more than he would like in states like Georgia with large black populations. I think it is more likely that the electoral map from 2000 and 2004 stays about the same, but McCain gets a lot bigger share of the popular vote and picks off a few smaller states like New Hampshire.
McCain may turn NH red (while losing everything down ballot,) but I think there will be a number of former red states from the past 2 elections turning blue. I don't expect McCain to do anywhere near as well as Dole did.