I hope Biden is able to outshine her and not do anything damning, but here's the beauty: Palin can rock, Biden can suck ass, and it won't, in all likelihood, affect the election. Historically, veep debates don't make a damn bit of a diff to how the election turns out (think Bentsen-Quayle). This year has been full of surprises, but I don't think this will be one of them.
So, my prediction for the night is, Palin holds her own and it gets called as a win for her. And a week from now, no one cares.