We've certainly seen the PS3 before, both at E3 last year and at CES in Januray, but we have no idea if either of those times the devices were thoroughly working models. It's said that though graphics were being generated from these boxes, they were just rolling demos.
Now there are rumors that the first playable Sony Playstation 3 will be presented at next week's Taipei Game Show. It looks like Sony is going to devote a full quarter of its 80-booth space at the show to the next-gen gaming device, so this could be the very first fully operational demo. Fingers crossed.
Sony plans Taipei Game Show splash for PS3 [reghardware]