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.
Wha? The halfing will double energy costs, and there is 48TH in the BFL waitlist thread made public (actual orders are probably much greater) I understand there will be 1000 bASIC units made, so thats another 54TH, and then another 20 from avalon. So thats 122TH. Plus whatever deepbit and the other efforts do.
Just from the numbers there and the halving you have a 12x increase in power usage per unit reward 10x if all the existing hashpower turns off as a result of the increases, and I think its not unrealistic to call that a conservative lower bound. And this should all happen in the next couple months? Thats not skyrocketing enough for you? It will rescale the difficulty charts so significantly that the introduction of gpus will be nearly invisible on them.