The Palin Biden debate ends pretty much as a tie, with Sarah Palin surprisingly holding her own against a far more experienced politician. Palin's answers seemed well rehearsed, and it appeared her strategy was to have several good rehearsed answers and several good bridges to those topics. When Palin was spontaneous she seemed "off", but when rehearsed she'll be seen as spot on by her supporters.
CNN's trend meter indicated good marks for both, though it seemed to me Biden was pulling better with the Ohio undecided women who they measured moment to moment.
Overall affect on polls? I'm guessing not much. Palin will appeal to those who like her but this won't change many votes.