Linden nerds are currently peeing their pants over this new toy that will be implemented into SL. In their own words;

What is WindLight? How did this happen?

WindLight “simulates the ways that sunlight is scattered by the atmosphere under different climatic conditions, such as fog or haze”. Long story short: killer skies and kickass environments.

Linden Lab has teamed up with and acquired Windward Mark, who’s responsible for developing this visual excellency. We warmly welcome our new brethren!

Initial thoughts at this technology; it seems to add a layer of fakeness to SL.
While this may sound like an odd thing to say it should be noted that the skys are photorealistic, and because of this they appear to look a little out of place in the “cartoony” universe.

Lets wait to see it in action.