That said if you ask me who I think wins, I think it's Obama unless the economy takes a huge dive. Last two incumbents to lose were Carter and H.W. Bush both due to economic issues in my opinion.
Everything that happens from now until Sept/Oct is worthless. I think that's why McCain lost by such a huge margin. At the end of the day, gay marriage, immigration, etc. don't mean shit. As James Carville said, The Economy Stupid.
If the economy shows signs of growth Obama wins. If it deteriorates quickly Romney should win.