The Nintendo DS Lite went on sale today in Japan.

Lines formed in front of electronics stores in Japan and the new stream lined Nintendo DS was sold-out very quickly as supply was limited. The supply situation could stay problematic as Nintendo can only make 450,000 units in March.
The new Nintendo DS Lite features a much better design than the original DS. The screens are brighter and it is overall smaller. Apparently many older consumers are getting the DS Lite to play educational games.
Game store Lik-Sang has published a review of the Nintendo DS Lite. More details on the MSN Mainichi site.
As reported the Nintendo DS Lite only is available in white due to production issues with other colors.
Due to the high demand in Japan for the DS Lite and the production issues I assume it will take still several months until Nintendo is releasing the DS Lite in the United States or Europe.