It doesn't sound as if anything has been done about the VR sickness problem. Wearing bulky screens in front of your eyes probably doesn't have much of a future, but I think that augmented reality using something like the EyeTap device has a much bigger future which extends significantly beyond gaming.
My understanding is that the sickness was in large part due to the latency (Solved by Carmack). Beyond that it's just a matter of getting the perspective correct (Also solved by carmack).
It occurs if there's a sustained mismatch between your vestibular sense and visual odometry. That's ok if the game only involves looking around in a fixed position, but if the avatar is walking/flying then you're likely to get VR sickness, no matter what the frame rate is.
Apparently, VR users do habituate to the effects after a few days, in the same manner as space sickness, but in the intervening period there can be some unpleasantness.
