I really haven't followed Posehn's career but I do know of him from the Metal By Numbers video he did and some of his bits on Mr. Show and the Sarah Silverman Program. When the new video single, More Metal Than You, came out and I found out that he was coming to the Valley, I was stoked! The video is pretty awesome of course:
I saw him live and he is fucking hilarious! He did not do a whole lot in the way of metal references but he had fantastic delivery and just all around great jokes. I'll have to pick up his albums soon.