Neither. He's going to maneuver to get himself nominated and elected as the independent, bipartisan option.
you're talking about 2012? he's finished, dude
No; if the VP choice goes to the Senate, they don't have to choose Palin or Biden. Given that choice, you'd have to think that Republicans would be very, very eager to choose one of their own in Palin's place. They're making happy noises now, but they don't respect her and don't want her around. A Republican wouldn't win, but I'm sure Joe Lieberman convinces himself he could get Republican support and enough Democrats to emerge as a compromise pick. Beside, he sees himself as a man of destiny.
I would vomit if that were to happen. Hopefully, Obama would send Lieberman to undisclosed locations for the duration of his presidency.