With all the rumors about Sony focusing on APU and stackable memory, there is a really good chance that final mainboard design will be fairly simple. If they dont elect to use dedicated GPU [

] then they will not loose much if they aim for 350$ price. 1-3 game purchases will bring them back to the profit.
IMO, with only APU the max they can get is 2Tflops, around 8-10x increase over PS3 when we account optimizations that are part of the new hardware and software. That's not bad... but its far from maximum potential of 200W console.