Ernie has created a Silverlight plug-in for Lutz Roeder’s Reflector.  Reflector can already be used to view Silverlight v1.1 CLR assemblies, but this plug-in enables you to look at the code for any Silverlight app (managed or javascript) simply by providing the URL.  This is very handy tool for anyone looking to get into Silverlight development as it lets you quickly answer the “How’d they do that?” question.  Of course with this comes the inevitable issue of IP protection.  Ernie’s post has more information on that topic and a set of good links for obfuscating managed code.