Valve's Chet Faliszek has said pretty clearly in the past that Half Life 3 won't be a VR game, and I think that's pretty realistic. First person action based shooters don't translate well into VR. Any kind of locomotion that isn't walking around your room-scale space or teleporting just feels incredibly jarring, and it very quickly makes you feel motion sick.
So it'd be a pretty significant change to what we've come to expect from the Half Life games if they made it a VR title.
So it'd be a pretty significant change to what we've come to expect from the Half Life games if they made it a VR title.