Cree is claiming a efficacy record for a white power LED. In the lab, a packaged 1x1mm die produced 173 lm of 4,689K white at 350mA and room temperature.
Cree devices on the market are currently producing just over 100 lm/W and those from Lumileds just under 100 lm/W.
The Cree announcement could mean this level of efficacy reaching mass production sometime in 2010, as lab developments appear to be taking somewhere around two years to hit the shelves.
For example, in 2005 Cree announced 70 lm/W at 350mA in development, and these devices became available in 2007. When Lumileds revealed lab efficacies, and it has not done this for a while, it too took around two years to make them available.
4,689K is a cool white, and cooler LEDs tend to be more efficient, whereas lower temperature 'warm white' LEDs are proving more popular for illumination as they are more similar in hue to incandescent bulbs, and technically offer improved rendering of red-coloured objects.
See also: Electronics Weekly's roundup of content related to LEDs, with a special focus on both white LEDs and coloured LEDs:
LED technology - White LEDs
LED technology - Coloured LEDs
LED technology - LEDs general
LED technology - LEDs Lighting