Steve's posted a short note from Gearbox today, where he is attending the PC Halo Fanstock event:

Met some really great people at Fanstock this weekend. I have the privilege of sitting in Gearbox right now. There seems to be an abundance of Half Life games everywhere. Halo PC is of course why we are all here.

F.org, as well as other sites attending the event, should have more updates throughout the coming hours and days.