The new 3ds Max Design 2009 includes new technology for simulating and analyzing sun, sky and artificial lighting to assist with LEED Indoor Environmental Quality credit 8.1 certification (from LEED Reference Guide: Submittals … Provide area calculations that define the daylight zones and provide a summary of daylight factor prediction calculations through manual methods or a summary of computer simulations illustrating that the footcandle levels have been achieved).
The new Exposure technology included in 3ds Max 2009 Design provides output not only as rendered images but as numerical data (downloadable as Excel data), representing the distribution of light intensity across space.
Update: 3ds Max now supports EnergyPlus weather files which are available from the U.S. Department of Energy. This weather data is available for 1042 locations in the USA, 71 locations in Canada, and more than 1000 locations in 100 other countries throughout the world. You can load those *.epw files that are based on measured information to get actual weather averages to generate the sky conditions.

See this post at for a step by step tutorial.
Watch more in depth demonstration videos on the Autodesk Architecture Resource Center .