you can run linux on dreamcast - nothing fancy though, too slow to be usable and no ram left after boot up
its biggest attraction as a console atm is that it is the only reasonably specced console that sports a cd-rom (dubbed GD-ROM because it supports larger capacities) - which enables the average user to just burn software and play around with it..
some its games are amazing, even by todays standards
it would make a good candidate for UAE, but noone has ported it yet. Having said that a bunch of guys over at
www.dcemu.co.uk have recently announced (about a month ago) that they are working on a universal M68000-compatible emulator to support software from Amiga 500s, Atari STs and early Macintoshes...whether this materialises we will have to wait and see
There was someone here a while ago that claimed to have booted Workbench on dreamcast, or was it PS2?