As another audio and VR guy I also think that true 3D sound - as well as physics - will be even more important when a user is truly encompassed in a virtual environment. It will no longer be good enough to simply hear an animal ‘somewhere to my right’ as stereo or surround sound would render it. The sound needs to be realistically matched to the proper azimuth and elevation (say 30* right and 50* down).
Hopefully we can get to a point soon where we can nail the direct sound with the proper HRTF profile; then do a few of the first early reflections; take a stab at the late reflections with more and more general approximations; and finish with a room-appropriate reverb tail.
At least one can dream…