> Plenty of LED replacement household lights already on the market.
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http://store.sundancesolar.com/120voacledre.html
I'm aware of that but the amount of light they produce doesn't compare with conventional bulbs. For example a 60W filament lamp produces 600-700 Lumens. The brightest LED lamp on the above site (72 LEDs) produces only 200 lumens - so it's comparable to a 20W filament. Worse it achieves that light output over a narrow beam angle. As far as I am aware there isn't yet an LED replacement to the 50W halogen downlight people use in kitchens...but it may not be long coming.
In the UK an "energy efficient" lamp is classed as one that produces more than 40 Lumens of light per watt of electrical power. As far as I can tell you can't yet buy an LED "replacement bulb" that achieves that figure (Some CFL fail to meet that as well). Prototype LEDs have exceeded 70 L/W but really bright commercially available LEDs come as a die on a small substrate. That's because they need a heatsink. That limits there application to custom light fittings eg car headlamps.
Hopefully it won't be long before LEDs are bright enough for serious use but they aren't quite there yet in my opinion. Meanwhile I'm using light fittings fitted with "warm" tubes. These are much nicer than standard colour temperature tubes.