"Use Expression Blend 2.5 to create and modify managed Silverlight 2-based applications. Expression Blend for Silverlight 2 includes all of the features in Expression Blend 2 but has not reached the quality level of Expression Blend 2 for WPF or Silverlight 1 development.

Expression Blend 2.5 June 2008 Preview (build 2.1.1113.0) has been updated to work with the Microsoft .NET Framework 3.5 Service Pack 1 Beta. To determine which build of Expression Blend 2.5 you have installed, on the Help menu, click About Microsoft Expression Blend."