Minnesota has been trended Republican for several years now, so I think we have a great shot at Minnesota (Al Franken should be worth 2 points for McCain at the minimum).
Southeast Wisconsin is in the Chicago media market and is traditionally very liberal (i.e. Madison). Wisconsin would be a very hard flip. If McCain takes Wisconsin, he will take Minnesota, Michigan, and possibly Pennsylvania.
Minnesota and Michigan are the best bets for flips in the upper midwest. Either one solidifies McCain’s election.
No WI is more in play than the other three states. Bush lost WI in 2004 by 11,000 votes and in 2000 by 5,700 votes.