I think next year's general election will have one of the weakest line ups in recent memory. The Dems have poor candidates, while the GOP have some even worse ones.
I'd predict the Dems to take it just because the GOP needs to flip too many 2012 Democrat states to win the election.
Flipping states isn't as hard as people seem to think it is (Obama flipped lots of states in 2008, as did Bush in 2000, Clinton in 1992, Reagan in 1980, etc.), but I agree that the Democrats will win because the Republicans have such terrible candidates, and their views tend to be rather unpopular these days.
Also, obligatory http://xkcd.com/1122
Republicans are today in the same position as the Democrats were from 1968-1992. They need their version of Bill Clinton, a moderate with a strong record to get out of the wilderness, and I believe that person in John Kasich