It's actually the head of super reddit fan, Chirag Mehta (half of the duo responsible for Sched.org and Chime.TV). I was at CommunityNext with some of our mutual friends and we decided to make his day and immortalize him in the logo for no good reason other than to make his day.
It didn't scale down too well, as he didn't even recognize his own face until one of us told him. But he was fairly pleased once he understood.
I should also mention that he's going to be helping me with a neat side project and I needed to butter him up. Stay tuned, this is not the last you'll hear of Chirag -- although it's probably the last time you'll see his face on the logo.