Romney could lose Ohio and NH, but win CO, VA, NV, IA, FL, NC. This will result in a 269-269 tie, with Romney winning the presidency by a vote in the House, and Biden winning the vice presidency in the Senate. Romney/Biden '16!
Friend of mine made pretty good argument that a tie would end up not as Romney-Biden. His expectation is that it would end up Romney-Clinton. In a nutshell, why would the senate pick Biden when they could pick anyone? They could even choose Obama for that matter. But there are two months between an electoral tie and the senate electing the VP. The Clinton's will get Hillary assigned to the VP spot. The real question then is in four years if the economy is strong again, will she try to run against Romney or try to stay on his ticket?