Recently in SSL Solid State Lighting Category

"Incandescent light bulbs waste 95% of the energy they use as heat. Phasing these out and replacing them with efficient alternatives can help reduce emissions and energy bills.

"We are pleased that UK retailers and energy suppliers are voluntarily phasing out these lamps before European rules are introduced later this year."

Lord Hunt claimed the bulbs contained a smaller amount of the substance than mercury thermometers, which the EU has banned, but the government was looking at safer alternatives such as LED lights, which did not contain any mercury and had a longer life.

The move to low-energy light bulbs is described as "one of the most positive moves the government has made recently".

Palace of Westminster claims to have saved 61% of its energy costs by swapping to low energy bulbs.

Read more at the BBC

If technology improves faster than expected, and opening category B prior to completion of a three-year waiting period would be in the public interest, DOE will advance the date for allowing products to qualify under Category B.

DOE's intent, is to substantially increase future performance requirements of LED Luminaires, and to  encourage continued improvement in technology selection and design of luminaires using SSL sources.   Products for a wide range of general illumination applications will be eligible.
 
The minimum luminaire efficacy target given for Category B is intended to rival today's most
efficient lighting systems using traditional light sources. 

T8 Fluorescent Lamp and Electronic Ballast Comparisons

For example, the best commonly  available high-performance T8 fluorescent lamp and electronic ballast systems are rated  around 100 lm/W. High-quality fixtures for these lamp-ballast systems are about 70% efficient, yielding 70 lm/W luminaire efficacy.
 
Based on current commercially available technology, the Category B level of minimum
luminaire efficacy is not achievable for LED luminaires.  However, DOE anticipates  performance will rise rapidly over the coming years due to on-going progress in LED efficacy, LED high temperature tolerance, power supply efficiency improvements, and luminaire design.
 
DOE believes a significant number of general illumination products will be able to achieve 70 lm/W luminaire efficacy within three years after the effective date of these criteria.