I really like the idea that, unlike inFamous 2, multiple power sets also give you multiple sources from which to recharge your health/energy. I think that's potentially a more natural-feeling progression than turning the power on in order to be able to recharge yourself.
Now I'm curious to see whether each power set shares the same energy pool or whether you have to drain smoke in order to gain smoke powers, drain light in order to use light powers, et cetera.
Separate pools would make more sense, I suppose.