I think maybe we're missing the point here. Small computers are nothing new. My laptop is small. Yeehaw. Regular desktops could also be much smaller, as most of the room in the tower is empty space. But that space allows for user serviceability, and upgradeability.
The cool thing here is that the price of a working computer is going to come way down. Not necessarily the high powered gaming or business related computers that we may be using, but the basic computers that will allow lower income families to join the computer age. Just as everyone in North America now has a colour tv (a rare item when your parents were growing up), soon everyone will be able to have a home computer. Huge implications for how society works. Maybe the technology will even translate into less developed nations, so that poor families there will also be able to afford a home computer. That access to information could prove to be a very powerful tool indeed.