Read original post at Jeff Handley's Blog
On December 9, 2011, Silverlight 5 was released. As always, RIA Services is included in the Tools for Silverlight, and this new release included our V1.0 SP2 final build. We refer to this as our RTW build, meaning Released-To-Web. In addition to the Tools installer including WCF RIA Services V1.0 SP2, you can also find the standalone installer on Microsoft Download Center. The silverlight.net/getstarted/riaservices page was also updated to reflect the new release.