Wow, that was probably one of the weakest speeches to a national audience I've ever seen! If W is considered a bad public speaker, Kaine has to be considered worse than him--and there was just a camera and maybe his wife in front of him!
I think the President gets better and better at his speeches... in the beginning he had that deer in headlights look until the 911 speech in congress and then he started to come into his own and has improved steadily.