I love this idea! I think it would be great on a notebook. People could take their games with them when they travel. I’m not sure how feasible it is though… PS3 requires some pretty hefty hardware. Ben Heck made a PS3 notebook and it’s pretty huge:
http://www.engadget.com/2008/04/10/the-ps3-laptop-from-ben-heck-to-engadget-with-love/)
It might be possible to build a PS2 into a computer though. Which would still be pretty sweet.