5) The main thing limiting it at the moment is that normal UI interactions can get a little ... intense. I brought up a Safari webpage and the combo of the bright colors, eye-tracking on lots of links, gave me real sensory overload. Maybe you adapt, but it felt like the rest of the interface -- which is quite muted and visually subtle, is toned down by comparison. We may think you want a million windows floating in 3D space, but I'm not sure that's tolerable, even for us.