I was wondering this myself, but after hearing about the Nailgun (and the relative ease of the new difficulty level) I'm starting over. Hell, it was a fun game and worth another playthrough. Plus, I missed some of the achievements from the first one, like killing so many with such and such a weapon.
As a retarded faggot, I find many of the comments I hear on XBL quite off-putting.
Peace, Love, Krisko Disko