I asked if you could run Doom 3 on a PS3 years ago but you cant because the linux doesn't use all the features of the PS3 like the GPU because it wasn't coded too.
SOMEONE has to set the ball going if people want a bevy of games on linux.
Id be more inclined to dual boot if they did this, id be able to play some Valve titles on linux.
Mac's have taken off especially Mac books and the fact that when you buy a copy of a Valve title you get one to use on Mac is cool.
Plus doing the Mac client it allowed Valve to develop for PS3 themselves since the architecture is similar. Maybe they are worried that no one would port to linux which is strange because i would also be worried about the port to Mac rate even though its not terrible not every company is willing to port over to another OS for whatever reason.