According to Tom's Hardware, "Sony is apparently working on a 65 nm to 45 nm migration of its Cell Broadband Engine. Sony claims that the chip area size will be reduced by 34% and the 45 nm Cell will consume 40% less power than the 65 nm generation. The company also works on improving the design for manufacturability (DFM) for Cell to simplify the CPU production process."
The Cell processor, obviously, powers PS3, although quite what a 40% reducrion in energy consumption would mean for the machine, apart from being good for the environment and you console not getting so hot, isn't clear. Someone will tell us soon enough, we're sure.