I thought the VP debate response was interesting. I wondered if there would be an uptick in McCain's support as wavering voters manaed to convince themselves that Palin wasn't a total disaster. However, it gave most voters a chance to hear Joe Biden who's basically been ignored on the campaign trail and I thought he came off very well.
Whilst, Palin failed almost totally, or coherently to answer any questions, Biden was knowledgeable and concide. When Palin stumbled over the Afghanistan commander's name and came out with 'McClellan' (I'm not sure if she was r
eferring to the civil war general or Bush's bumbling press secretary. It seems unlikely she would have heard of the general), Biden, following up, didn't correct her, or use the name McKiernan, but talked of our commander in Afghanistan. This followed on from the tactics Obama used in the preidential debate when he maintained his calm demeanor against McCain.
Here's the graph showing the 538.com stats as they have moved over the last three months.