Although I know that I personally will never play anything on one (nobody I know is crafty enough to put something together), I definitely respect this little guy. Looks like you can plug a couple SNES controllers right in there, load your homebrewed game off an SD card, and S-Video it out to your TV.
The Fuzebox doesn’t have anything built in but a really basic BIOS and it has about the power of an NES, but I’m sure the open source community that’s supported such systems as the GP2X and Dreamcast will be on this thing as well.