Curiously, it could end up with just Biden. A few months ago the Slimes ran an article where it interviewed a group of law professors (I don't have the link) who opined that McCain, having been born in the Canal Zone, was not a "natural born" citizen. If SCOTUS determined that argument to be correct and it was discovered that Obama was actually born in Kenya, we'd probably be left with Biden. Of course, we wouldn't need to worry about any threats from the rest of the world for a while because they'd be too convulsed with hysterical laughter about our Three Stooges level of ineptitude to do anything.
Does anyone know if any other candidate received even a single electoral vote? If so, we could end up with that individual as President.