There's still a lot of progress to be made on the ASIC front. The current generations of Bitcoin mining ASIC are brutes, several places mention that the Avalon

There's still a lot of progress to be made on the ASIC front. The current generations of Bitcoin mining ASIC are brutes, several places mention that the Avalon miners use a 120nm process (think Pentium 4), which means that there's a lot of headway in terms of speed and power consumption that can be made in the future.