Valve has a presentation at 3pm on the March 3? That is a lot of 3's.
http://www.ibtimes.co.uk/valve-gdc-session-schedule-teases-possible-half-life-3-announcement-1490069
http://www.ibtimes.co.uk/valve-gdc-session-schedule-teases-possible-half-life-3-announcement-1490069