If Obama loses in a close race, and the Dems hold the Senate, I think you’ll see him as the party’s nominee in 2016. If he loses big, and the Republicans increase their majority in the House and take the Senate, then things will get interesting for the Dems in 2016. Obama’s enormous ego will cause him to seek the nomination, but the party will blame him for the 2012 disaster and seek another candidate. Hillary and Biden will be too old. (Hillary looks horrible now - just imagine what she’ll look like in 4 years!) As someone else pointed out, the Democrats have a weak bench. They’ll have to manufacture a new “rising star” in the party.
Ed Rendell, disgusting Schultzoid party hack from Philly and former governor of Pennsylvania, is out and about making noise -- looks like he sees things pretty much the way you do, and he's making his opening moves now.