Anyway, I'd say Rig 2 would pull a bit more power than Rig 1 if the E2160 is overclocked. However, Rig 2 would provide substantially more CPU power if you're doing folding, encoding, streaming, virtualization, etc.
My E2160 fileserver that I ordered will be overclocked and folding obviously We would always welcome more people...
Actually, it's a bit hard to tell because while the CPU might consume more, it's also more efficient (65nm vs 90nm) and DDR2 is also more efficient. I think that overall, the newer rig would be more efficient especially if it is paired with a 80+ efficient PSU.