How's that supposed to save them money? The Cell already exists, not to mention all successor forms. Improving it would cost them less than actually contracting out AMD to design a CPU/GPU Fusion based die, not to mention this is gonna be based on x86 tech? I don't see how this could work well on a console, at least Nintendo and MS still use IBM PowerPC (ARM based) CPUs.
But again, this is only a rumor. Perhaps it's only the GPU, or perhaps there's indeed a benefit behind that move. Who knows. We won't find out the full details about the full specs before 2013 (E3? Or earlier).
More importantly though for a successful launch are the actual launch games.
Also, MS and Sony could do something really nasty with the input devices, like doing stuff you can't do with Mouse/KB, thus rendering PC ports useless. God hope developers are continuing making AAA PC games.