Looks neat, but I envision an "octopus" of cables hanging off the thing, (hard drive docks, power supplies, USB hub, etc...) that kind of negates the tiny footprint.
Scatter the pieces all over, or put all the pieces in a bigger box. If you want full PC functionality, it's a "pick your poison" scenario.
This has a few very good applications (E.g. information terminals, annoying advertisements at POS, etc.) but I'm not sure it's a big step forward for those who expect to replace the box on the desk.