well, that headtracking technique has a serious flaw .. how do you create the same effect for several viewers at once? the screen has to adjustable to 4 or more people for that to become mainstream tech
I mean, you can see it if another person's head is tracked, but then it's not better than 3D now.
by the way, apart from that it needs:
- fast cameras (I think at least 240fps)
- a lot of processing power and very good software for headtracking with very little input lag
but I think it's less expensive to create a "real" 3D image than to adjust a TV (with motors or sth.) for several people at once to make them experience the 3D Window effect created by headtracking
edit: one method I can imagine to make it support 2 people (not more) is to use the light polarization technique, but that cuts the vertical or horizontal resolution in half and people would need to wear glasses
