My Model B Raspberry PI is on it’s way. With a shipping date of 2012-03-23, I hope to have it before tax day! This certainly seems like a better investment than an Apple TV or a Roku box as a media computer, but with the ability to run Debian, it will be a great low-powered general purpose computer.
One possible interesting application of these is to use Synergy and a bunch of networked Raspberry PI’s and a lot of cheap large HDMI screens. These devices make it possible to easily build massive displays at a fraction of the cost and power of existing systems using pre-existing free software. I’m sure that many more creative applications are possible.