Y'know, the smell wasn't so bad when I was there. No worse than some professional sports games I've been to - any large group of people being moderately active for 12 or 14 hours starts to smell a bit.
I asked some of my friends about it, and they said that the advent of online game really mitigated the "gamer" smell over the last four or five years - the worst of the worst, for the most part, are now staying in their parents' basements playing Everquest or WoW. The sort of people who go to conventions are the sort who like the face-to-face human interaction, and those people (for the most part, with some exceptions, of course) have the social skills to at the very least bathe and use deoderant.
-Alex