Just heard about this tool from Pandurang (when going through his slides from Virtual Tech Ed)

Similar to Reflector for .NET Applications there is a tool to dessicate the Silverlight applications. You can download this from http://silverlightspy.com/

Note that this is a Clickonce application and you will have to ensure that your computer has the minimum requisities before installing this tool.

Minimum softwares needed

Internet Explorer 6 or higher
Silverlight 2 (Beta 2 or Release Candidate 0) runtime
Windows Installer 3.1
.NET Framework 3.5 runtime

Will let you know how this measures up after testing this with few silverlight applications.

Read the complete post at http://mrajesh.spaces.live.com/Blog/cns!803D08B41461A51B!319.entry