In the future LED is the way we light everything in your society reef included. It is most efficient and we can produce whatever spectrum we want by manipulating the LED element. With that said, I thing LED for reef have not arrived yet, but much better now that it was 2-3 years ago. One of these "full spectrum LED unit" maybe the way to go now, but still cost a bit much.
For me I am sticking to my MH for now. I will build a fish room in the near future, very likely I will LED light then.