"Atrios," until today the most famous anonymous blogger (and arguably the most famous liberal blogger), is among the bloggers attending the Democratic convention. So is Dave Winer, previously of the Berkman Center, who pointed to a post on TalkLeft (which confirms my suspicion that bloggers are the nicest people) and had this to say:

Hearing that [Atrios was there] I got out of my seat, introduced myself to the Talkleft blogger (she said on her blog that she's sitting next to David Sifry who I know, of course), she pointed out Atrios, I asked if I could take his picture, and he said yes. Now there officially has been news at the DNC. The uncloaking of a blogging super-hero.

The picture that Dave took is here. Confirmation that this is not just some big convention blogger hoax comes from the "copyright" notice at the bottom of all Eschaton pages:
Eschaton -- a weblog by d u n c a n b l a c k

Obviously, the next question is, "Who is Duncan Black?"