What I'd /really/ like would be a fully Lua-based operating system. Sure, some some C or assembler here and there, but the least possible.
Taking something like eLua booting on bare x86 and make it up from there.
Unfortunately, I cannot help but look at Lua OS as wanting to be just, as someone put it on OSNews, a "Linux distribution that is awesome and uses Lua for a lot of stuff."