Came across this info. Nvidia says PS3 graphics chip still in development
Nvidia has revealed that the RSX GPU in the PlayStation 3 is still under development, and that the hardware has yet to be finalized.
Speaking at the JP Morgan technology conference, Nvidia CFO Marv Burkett said that the RSX chip has yet to be manufactured by the company, and that Sony will ultimately be producing the chip itself.
Hence, the E3 tech demos weren't running on the actual RSX GPU but on an upcoming next-generation PC chip, which shares similar capabilities to the PlayStation 3 GPU.
This further puts a cloud over the true graphical capabilities over the PlayStation 3, which initially blew away attendees with groundbreaking graphics that seemed to overshadow the Xbox 360. Microsoft has meanwhile fired back, releasing comparative specs between the 360 and the PS3 -- which supposedly show that Microsoft's console is superior to Sony's.
However, even the 360 console hardware has yet to be finalized; most game demos were running on Apple G5s in an Alpha or pre-Alpha state. Especially for the PlayStation 3, it will likely be at least a couple months of waiting before games can be seen in their true form.