It's small, it's sexy looking, all ready to hook up to your TV, and has ethernet for doing networking (LAN and broadband). That's much better for a family PC in the living room than the standard LCD/desktop eyesore. Don't get me wrong, I prefer good, powerful workstations, but I have to admit my wife is right here... they look ugly amidst the living room furniture.

We only run linux in our house, though, so YMMV on the usefulness of linux on a Playstation.