One potentially serious obstacle I can see is the ultimately divergent needs of cellphones and HMDs. The latter have tremendously benefited from the ready availability of cheap, high-definition displays developed for the former, but from now on, it probably won't work quite as well. Most phones are fine with 1080p displays; some feature 1440p displays, which is better for VR but still not enough. Is anyone going to make 4K displays for cellphones? I'm not sure. What about 8K? That sounds preposterous for a phone, but for HMDs it's probably the sweet-spot.
That said, HMD manufacturers can probably get away with dual 1080p displays or something like that, at least until they reach sufficient volume to get display manufacturers to start making products specifically for VR.