Expression Blend 2 Service Pack 1 enables creation of Silverlight 2 Content
Expression Blend 2 Service Pack 1 updates the supported Silverlight platform to Silverlight 2 which enables you to take full advantage of the new features available in the platform.
The Expression Blend 2 Service Pack 1 exposes two new features of the platform, control skinning and the Visual State Manager, that for the first time allow designers to take complete control of the interaction model of Silverlight 2 based applications.
To download Expression Blend 2 Service Pack 1 visit https://www.microsoft.com/expression/ and click on "New Updates Availabe Now" on the right hand side.