One thing that radio could not convey (aside from the usual body language stuff) was the fact that McCain never once even looked at Obama during the entire debate. Given that the candidate's podiums were very nearly facing each other, that was not an easy thing for McCain to accomplish. In fact it appeared peculiar and uncomfortably deliberate. I've no idea what McCain's reasons were, but the effect was that McCain appeared offended to share the stage with a black man.
Wow, what odd behavior for an elder statesman. I was amazed at how few umms and uhs there were, and how quickly each seemed to jump right in to their respective responses.