I'm gonna use my myth box as a tivo and mp3/media player/server. put a nice big hard drive up on it. I'll run a samba server on it so I can stream to my other windows computers.
it'll also host all my mame/nes/snes roms which work with myth ot-of-the-box, and I hope to get a n64 emulator running.
let me know how it works out