Few notes about 3D perception in general...
stereoscopic vision is only one facet of what is needed for convincing true to life 3D.
Most other facets are already replicated on a 2D screen with 3D graphics cards...
But there are still a couple of facets that aren't catered for with this setup, including motion parallax (i.e. parallax of objects on screen relative to your own eyes/head, and not the parallax of objects in the screen from changing camera angle)... which can be handled with face tracking technology.
The last and probably most complex perceptual cue to emulate is focus. It can be fudged on screen, but really, we get strong depth cues from engaging the muscles in our irises which in turn changes our focal point. Two items can be close together on the X,Y plane, but be far on the Z plane - the change in focal distance helps to indicate how far something is.
There are technologies out there that change the pixel display based on the angle at which you see something (the other form of screen based stereopsis), so it's concievable that in the future, we might be able to get light directed at arbitrary angles, in turn forcing us change our focal point to see it in focus properly...
Still, stereopsis is as big a move towards 3D perception as lines converging towards a vanishing point is.