Update 20120201: Fixed some issues with project templates, improved them.
Update 20111218: Added Silverlight 5 to the mix.
Update 20111007: Corrected a small error in the MSI that could cause the setup to fail
This is another preview of MVVM Light V4 and is tagged "beta 1". The API should be pretty stable. I am planning another beta ("beta 2") before making a final V4 release.
List of changes is available at http://www.galasoft.ch/mvvm/installing/changes/