>Anyone else seeing an analogy here between Obama 08 and McGovern 1972? If he gets desperate enough, like 10 points+ down in the polls, do you think Biden wold resign for personal reasons and Hillary be placed on the ticket? I'm thinking it's a real possibility.

It is not going to happen. Firstly, Obama will not go down in polls so much. Secondly, Biden will not resign. More important thing, imho, would be avoiding mimicking Dem-sponsored attempts to talk Palin into resignation just few days ago.