A nice idea and a project I'd love to do myself but of course don't have the money.
I would certainly be interested if it ran Morphos. But I think to get a significant number of Morphos/AOS4 users on board you'll need something with a higher clock frequency than 1Ghz. I know numbers don't tell the full story but it's a psycological thing.
From a Morphos perspective a microATX board with the single core MPC8610 and plenty of expansion possibilities would seem to make the most sense - a Pegasos II replacement. Morphos is coming to Mac mini so the small compact less expandable side of things is already covered.