Obama's not going to win in the south -- and he doesn't have to. He can easily attain the 270 electoral votes without any southern states. There are ameliorating factors, though. Black people (a population with usually low voter turnout) are pretty excited about Obama and they are registering in record numbers. The races will be close in Virginia and Florida. John Edwards didn't really add anything to the Democratic ticket in 2004.. in fact, he couldn't even get a higher percentage for Democrats in his home state of North Carolina. His rural-populist message is really out of step with the times and he has stated that he does not want the vice presidency.
There is one southerner Obama could add as VP who would deliver Virginia and Florida -- Jim Webb. The man served as secretary of the Navy during the Reagan administration, he served in Vietnam and has put the Republicans on the defensive --- as a freshman senator. I worked on his campaign and will be the first to say, he needs some "people-skills" work but he pulled it off.... defeating someone who was being groomed for the GOP presidential nomination -- in a red state no less. He would be the perfect person who has a background in defense and fits into Obama's overall vision of change.
Obama has little to worry about in the midwest. Wisconsin, Iowa and Minnesota all overwhelmingly chose him in the primaries and he's guaranteed to carry Illinois. There's work to be done in Ohio but I think he'll be able to pull it off there, too. Indiana is a red state that he had no chance of carrying anyway.. The same thing for Nebraska, Kansas and the Dakotas.