PS3 cpu was a weak core processor, with 6 SPE's for floating point math.
Cell is basically a dead end design, whereas AMD's gpus are some of the most cost effective floating point monsters out there. All AMD needs is some decent amounts of cache integrated into the gpu (hint, unify cpu and gpu L3 cache, which I think they already plan to do), and a bulldozer derived cpu with tight integration with the gpu would be a far better design than cell ever had. AMD is hurting right now, so they might give sony a sweet heart deal on costs, maybe even sell the design.
That said, last gen of consoles had a 200W design TDP, while the hottest thing to ever grace an AMD socket was only 140W. Will Sony leave that much power budget on the tablet and go for a slimmer, smaller console, or would we have the freaking AMD cpu ever produced?