Virtual reality isn't a fad. It's too amazing and immersive to just go away. It's going to start out slow, because mainstream gamers won't pay $400+ for what amounts to a new controller, but as the technology gets cheaper (and it will) then VR will pick up steam.

3D TV never picked up because it's silly to expect families to sit around in their living rooms with special glasses on. And also, 3D TVs just aren't that cool. The pictures aren't that great -- they fall way short of what you get in 3D movie theaters. VR is a completely different animal. It's going to cause a resurgence of hardcore gaming that we haven't seen since the early days of MMORPGs.