Some months ago, BumpTop appeared from Anand Agarawala. “Physical Desktop Interface” using physics to replicate and show what will be possible in the future.
Today, Sony has this cool video demonstration of the future of the desktop expanding from the laptop screen to the desktop.
With the emergence of devices such as holographic projectors, the ability to show light outside a device without heavy and battery draining optics will drive the user-interface beyond the flat screens we have today.
TechZone recently published an article looking at games technology, and its application to the desktop.
My opinion is that we have yet to see the next “metaphor”; the power and the base abilities are there in the operating systems; but the application is languishing behind what is possible.