I just watched most of the debate again on CNN with a close eye on their tracker.  Holy shit, uncommitted female voters in Ohio f*&@ing LOVE Joe Biden.  My God, that orange line just jumped for him, time and time again.  The green line (guys) wasn't far behind.
Men seemed to respond better to Sarah Palin than women (shocked!).  But they also responded very well to Biden, especially during his closing statement.  The very final moment of the debate was the end of his statement, and both of those lines, but especially the women, were pushing the very top of the happy-meter.  
Additionally, as Palin started to speak, women tended to dial down a bit, warming somewhat as they listened.  But then often something Palin said would lose them again.
It's universally acknowledged that security moms lost Kerry the 2004 election.  Democrats haven't won men for decades; women are the ultimate swing demo.  And women in Ohio are the precious gems all campaigns dig their fingers off for.
I think it looks possible that the pick of Joe Biden, especially as compared to McCain's crude, ugly play for Hillary voters, might turn out to be a strategic death blow that the Obama campaign quietly dealt to McCain's chances some six weeks ago.