Report on LED lighting points to technology being 2015

Lit Up: an LED lighting field trial - by the Energy Saving Trust suggests that LEDs will dominate the market by 2015.

Note: the LED case is not wholly clear cut. The energy saving, and the longevity of LEDs are massive advantages.  There have been questions about the composition of the white light - with some research suggesting that the proponderance of blue light may interfere with producation of melatonin which regulates sleep cycles.