This guy has a screenshot of the PS3 user interface, which shows a whole load of stuff going on in the background.
Apparently from the news conference from where it was taken, the demo was showing how the PS3 can simulataneously run and display multiple HDTV streams, a web browser, a PS2 game, and various other images on the screen at the same time. Wow – talk about information overload, but that is surely impressive.
Notice how the icons follow the same style as what is currently used on the PSP.