All he needs is one of these states to win, so he's very well positioned to win the election at this point, even if a comparable number of Bush voters come out to the polls on Election Day.
Polls for "likely voters" are quite close between Kerry and Bush, so for the battleground states to be increasingly tilting towards Kerry, it seems obvious that one (or both) of two things is happening.
1> Established pro-Bush states are getting even more pro-Bush.
2> "Likely voters" is less of a factor in this election, and voter turnout will be higher than in previous elections.
That said, having more "cemented" Bush voters in uncontested Southern states won't help Bush in this election, and larger turnouts will almost certainly indicate better results for Kerry nationwide.
Still, wouldn't it be amusing if Kerry won the election with fewer votes than Bush?! As much as I'd hate to see our country further divided, you have to admit that it would be amusing to see Republican pundits wail at the inequity of it all.