I only saw a bit of Kerry's speech but, from the little I saw, I'm betting that he had a recent botox treatment. His face never moved above the eyes.
I heard him call on Bush to raise the tone of the campaign... then he implied that Bush and his Attorney General ignore the Constitution. He made a lot of similar implications. At this rate, mudslinging would be an improvement.
The Daily Show did a film on Kerry's principal qualification - he's not Bush. At least one media outlet admitted it.