A Hungarian company named Holografika is working on a true 3D display. They have been offering their HoloVizio system($39,000) for a couple of years for medical and visualization purposes. Apparently it uses two screens that send rays of light in appropriate directions to make the image seem 3D. Here it is in action at Siggraph. There are also full divx videos on their main site.

IEEE Computer has an article on limits of human vision and how were moving toward that goal. While the highest HDTV content has(all approx) 2MP, theaters' is 10MP, but human vision can discern on the order of hundreds of megapixels. That's not even taking into account the remarkable dynamic range. We got quite a long way to go.