This released fixed a number of minor bugs. You will need to remove the current installed version before downloading and installing the new release at http://www.microsoft.com/silverlight/resources/install.aspx. In fact, if you navigate any any site or page that requires Silverlight, you will be automatically pointed to the download location.
I did a quick test of a Silverlight 2.0 application. It just worked with the new release; no change necessary.