Well, software requirements and abilities drive chip design, and vice-versa. Many-core designs don't have power density constraints that are quite so restrictive, but they're hard to utilize to their fullest. Haskell can help with that.

I think the other side of the problem though is that if you can still get 100X performance from what we have today, but it costs 100X in power, you will still have a problem where few can really use it. Consider phones as one data point. Even quadrupling the power draw will make the chips unsuitable for use.