I think Obama's more likely to take her in as his vice presidential candidate.
Biden isn't going to do him any good at the polls.
But you may see a John Anderson sort of liberal independent candidate supported by the New Republic types.
I agree. Baraq's best hope is Clintonian plurality win in a 3-way race. I expect the 3rd party to be surreptitiously funded by Sorosbucks. Maybe Charlie Crist if he can pull off the Florida win.