Wikipedia is a source of considerable data on LED's. I haven't checked recently but for some reason 67 lumens per watt sticks in my brain. Of course this is only the beginning. LED's are here to stay and 'will' become the standard... one day. Unfortunately that day is not today nor tomorrow even. Halogen still has legs and will do for several more years. HID is no more affordable or efficient than LED so if one really wants to be on the cutting edge one could do worse than be an early adopter of LED tech.

H