Silverlight Tools RC1 for Visual Studio 2008 SP1
http://www.microsoft.com/downloads/details.aspx?FamilyId=c22d6a7b-546f-4407-8ef6-d60c8ee221ed&displaylang=en
http://www.microsoft.com/downloads/details.aspx?FamilyId=c22d6a7b-546f-4407-8ef6-d60c8ee221ed&displaylang=en
Visual Studio 2008 SP1
http://msdn.microsoft.com/en-us/vs2008/products/cc268305.aspx