Guys it's not going to be running games at 120fps. It's a 3d display remember. It'll be running games at 60fps in 3d. You need twice the refresh rate of the frame rate to display in 3d.
120hz = 60fps in 3d.
Edit: Actually I think i'm wrong, because it's a differnet display for each eye.
Will be running games at 120 fps.
The way a 3D usually works is by making sure each eye gets different information. For example a slightly different perspective of an object. How the headsets do this, is by being so close to the eye, (along with some lenses I believe) that the eye can only see its half of the information.
Essential instead of the hardware sending two separate images, one image is sent and is split by the headset.
The headset has the ability for 120 fps. This isn't one half doing something, then the other half does something. The whole screen is refreshed.
Frame rate is very important for VR. If a normal game is only doing 30 or 60 fps, it's not a big deal. The television is a light source that doesn't impact the user.
With VR, imagine turning your head and having it lag. The motion your eyes perceive wouldn't match up with the motion you made. This is one cause for motion sickness. The higher frame rates are crucial to keep this in check. Most of the other headsets are currently 90Hz.
With this headset, the motion can either be native 120Hz or can be reprojected to 120 Hz. So while the game itself may only be running at 60 fps, the headset can still display new information at 120 Hz. Sony already has a demo running at 120 Hz.
Visually the games aren't going to look like Uncharted, but they can still be very pretty.