Hallie Leighton http://tpmcafe.talkingpointsmemo.com/talk/2008/10/how-biden-can-win-the-debate.php
Makes some interesting points in her blog, but I think the strategy is fundamentally flawed: there is no way to "win" the debate. The expectations for Sarah Palin are so low at this point that if she manages to avoid tripping over her shoes, she will have "held her own" against Biden. And...
by all accounts, when Governor Palin is prepared, she debates pretty well. Expect her to do better than just not tripping over her feet.

So, how can Biden "beat" her in the debate? He can't. Any attempt to beat Palin in terms of a debate will be doomed to failure. Instead, Biden most forgo debating Palin as an opponent, and "take her under his wing" and HELP her (sincerely and with no trace of being condescending) to do her best in the debate. He should treat her almost as though he were her debate coach: willing to throw out helpful suggestions on how she might phrase things more clearly, giving positive feedback... "I believe that you meant to say this..." and encouraging phrases like "Interesting perspective..." and the like. But always with sincerity and respect. As though she were his student or daughter, practicing for a debate whom he had agreed to help prepare.
Then,  he should kindly and sincerely counter her assertion, and always give her the last word in every exchange. Play no gotcha games with her at all. Try to help her win the debate in every way possible without sandbagging his own position.
Contrasting his knowledge of the issues with hers by killing her with kindness and magnanimous gestures will go far further than one-upmanship in this situation, I think.