We've been waiting for decades for the release of this. I'm a HUGE fan of HL but not a fan of prequels. Hopefully this will showcase VR as a viable medium.
IMHO, I think Portal VR would have given a more immersive experience, along with less locomotion issues. However, I'm sure Valve has done their research.
My concern is, if this isn't met with favor, will Valve bow out of game development permanently? It just feels as if they are losing interest in new game development and would rather buy other studios and keep Steam chugging along. More money there..