Valve programmer Joe Ludwig will lead the TF2 talk, titled "What We Learned Porting Team Fortress 2 to Virtual Reality," and Valve research and development man Michael Abrash leads the second talk, called "Why Virtual Reality is Hard (And Where it Might be Going)." Abrash will focus on head-mounted displays. Not "displaying mounted heads" – that's at the Big-Game Developers Conference.
GDC 2013 is at San Francisco's Moscone Center from March 25 - 29. Other notable talks include a postmortem on FTL: Faster than Light, a talk from Capy on paid apps, one on The Walking Dead's art, and talks on mainstream games such as XCOM: Enemy Unknown, Assassin's Creed 3, Spec Ops: The Line, Hitman: Absolution, Mass Effect 3 and more. Peruse the list here.