It's not quite over yet.  If someone releases an efficient FPGA design on an affordable board then power costs won't matter at all.  FPGAs consume a lot less power per Mhash than any graphics card available today.  I recall reading on another forum section that an 80Mhash/s design is available and consumes only 10 watts of power, but requires a $600 development board.  40 watts for 320Mhash/s handily beats my 6950 which is about as fast and requires over 200 watts per card.

This however assumes two things: that someone will make publicaly available a cheap FPGA board, and the software to make it work.  If someone gains a huge advantage by employing FPGAs to hash then I don't expect them to cheaply share their knowledge or design.