I read the blog post and the docs linked from github and I didn't see anything about support for VR headsets on the PC. I take it this is VR only when using Cardboard on a phone?
That would fit with Google's approach to VR so far. Cardboard is a neat idea but a pretty bad headset experience compared to Gear VR or the desktop headsets. It would be nice to see Google's VR efforts playing nice with the rest of the VR ecosystem rather than them only supporting Cardboard.