When the PS3 first come out, it wont be compatible as there will be no driver available for it on the PC, however give it a few months and someone will write one that allows you to use it.

What would be even cooler would be if you could use it to play games on your mobile ! Sounds stupid, but there is lots of money to be made in mobile gaming (especially in Japan), so I would predict that in 12 months the new range or Sony mobile will allow this too.

Hey, who would have thought you can use your PSP as a wing-mirror in PS3 driving games... but you can !