Hi Richard
The main downsides of running it on Linux right now is the inability to run AU's or VST's easily, although I do believe that this may be possible with Wine these days, after the usual amount of configuration hell. My main desktop machine runs Ubuntu but I have to confess that all my studio kit is Macs running Protools, Sibelius or Logic. Every now and then I have another go with Linux, have a day of horrible problems then give up. Music for me isn't about the technology, so any problems tend to drive me mad very quickly. It's been a year or so since the last time I tried though, so maybe its time to have another go.
There are a lot of neat little devices like the one you llnked to, I myself have a number of little ARM boards here running Linux, but none of them are likely to have the raw horsepower to run EigenD unfortunately. You need at least 2G of RAM and a fast processor to get the most from it, and this is still beyond the capabilities of most low cost devices, although this will likely change over time.
I'd love to see EigenD running well on Linux though, please keep us posted as to how you get on. Jim was actually thinking he'd add support for the binary components in to the distribution at some point, so its possible that the Pico could be made to run well too.
John