That's only really a problem if you're strapped to a driver's/pilot's seat or some other system where the game isn't mimicking your body's movement. The current solution for that is one of those 6 DoF motion simulators, which might have to be good enough.

People with really bad cases of motion sickness have problems playing games on a flat screen let alone in VR. I don't think we'll be able to do anything for them in the near future.