The Silverlight 5 XNA samples, I presume are built in Visual Studio Professional editions as when when opening them in Visual Web Express 2010 it cannot open the Content Projects.
NB: I have reported the issue here, so watch out for a resolution there.
How can I use the Content Pipeline for a Silverlight 5 application using Visual Studio 2010 express editions? Or if that is not possible - how can I at least use the ContentManager to import pre-built .xnb files?
(I have all the requirements, apart from Pro edition it seems, and can draw primitives. I can actually run the platformer sample so there must be way)