I just wonder what the PR jackknife will be like if the difficulty suddenly skyrockets on a mere 60GH rig. The electricity argument them becomes very valid in the immediate future rather than in the further future.
The current network is rougly 350 60GH rigs. For the energy costs to skyrocket, we'd have to see 35,000 new 60GH rigs come online! That ain't gonna happen in the immediate future. Energy costs are a distant 3rd priority, behind date of mining start and initial costs. By the time it does matter, next generation ASICs will take over.