Beta2 adds a lot of new features (more details below), but is still a 4.6 MB download that takes less than 10 seconds to install on a machine.  It does not require the .NET Framework or any other software to be installed for it to work, and all features work cross-browser on both Mac and Windows machines.  These features will also be supported on Linux via the Moonlight 2 release.

Silverlight 2 Beta2 supports a go-live license that allows you to start using and deploying Silverlight 2 for commercial applications. There will be some API changes between Beta2 and the final release, so you should expect that applications you write with Beta2 will need to make some updates when the final release comes out.  But we think that these changes will be straight-forward and relatively easy, and that you can begin planning and starting commercial projects now.

You can build Silverlight Beta2 applications using the VS 2008 Tools for Silverlight and Expression Blend 2.5 June Preview downloads.  You can download both of them here.  The VS 2008 Tools for Silverlight download works with both VS 2008 and the recent VS 2008 SP1 beta release.