You might doubt that he's able to pull it off, but the physics behind it are pretty solid, and I think it could work. As you stated, the lenses obviously won't work for all screen sizes and viewing distances, but I think if it's optimized for desktop computer screens, it could be a pretty successful niche product. Hell I'd buy them for a 3d experience without ghosting that you can enjoy for hours because your eyes don't tire, even if the depth effect was worse than on nVidia's shutter glasses.