Silverlight templates for VS 2008...

If you  are running VS 2008 "Orcas" RTM .. you will need the "Silverlight Tools refresh for Vsisual studio 2008"..   released today...
https://www.microsoft.com/downloads/details.aspx?FamilyId=25144C27-6514-4AD4-8BCB-E2E051416E03&displaylang=en
Includes:
1) Website and item templates for SL 1.0
2) templates for Silverlight 1.1 alpha ( shipped in August)..