From wiki, linux on ps3
and the linux port of xbmc where I first learnd about it
Theres a link in there to the actually project site, but I cant access it from work. Dunno if its down or just blocked here.
As a side note, Im pretty sure Ive seen people talking about they use compiled betas of xbmc for linux, I could be wrong on this tho as I dont have a ps3 and no spare puter to run linux and eventually xbmc on yet so ive not looked in to it all that much.
I dont know if it will ever be possible (or rather officially supported) for linux xbmc to work on ps3, but Im pretty darn sure it will be done.