It appears that AMD may actually have won the contract to supply the chip. Former AMD employees told Forbes that AMD may play a "key role" in this next product. Both AMD and Sony declined to comment on the statement. Sony even denied the existence of a potential PlayStation 4.
Forbes' information attributed to an industry source with unknown credibility and unknown access to current information leaves quite a bit of room for interpretation. Does "key role" refer to graphics alone or more? In the end, there have been no recent news about the continued development of the Cell Broadband Engine, the heart of the PS3. The PS3 Slim received the most recent version of the chip, a 45 nm shrink, in August 2009. IBM, who played a critical role in the development of the chip, said in 2009 that it had halted the development of a Cell processor with 32 SPUs. The two most recent ISSCC events, which have historically been prominent venues for Sony to reveal new developments for the Cell technology, did not include news about the processor.
There is not much substance to this information at this time, but any part of Sony's next console would be an attractive deal for AMD. Of course, it is most likely that AMD would be the graphics chip supplier for this game console. Nvidia currently provides its IP for the RSX graphics chip built into the PS3. The GPU ships as a 40 nm version with a 550 MHz clock speed.