Plumer thinks the EPA will step in to fill the void:
Note that this is all likely to be costlier than a cap-and-trade system devised by Congress. There's not the same flexibility. One tool at the EPA's disposal, for instance, is the ability to require new power plants to adopt what's called "Best Available Control Technology" for pollution. But having the EPA pick and choose technologies is a lot less flexible and efficient than putting a price on carbon and letting the market sort out the cheapest, easiest ways to make cuts. That's one reason why polluters may start lobbying more heavily for congressional legislation once they see that the Obama administration is serious about wielding EPA authority.