If you are interested in using Prism for Windows Phone 7 I have successfully ported Prism 4.0 to it. The Prism port itself wasn't the challenge, it was the dependency injection container. I took the ContainerModel DI container from the
Mobile Application Blocks (http://Mobile.CodePlex.com), slapped an IUnityContainer interface on it, dragged over the applicable Unit Test from (Prism and Unity) and performed TDD until the test passed; there are close
to 800 passing unit test.
With the Prism and a Unity (like) container available I developed a multi-targeting framework where Desktop, Silverlight and Phone all use the same code base. The Silverlight and Desktop even share the same XAML with the Desktop application "only"
having a Resource folder (templates/styles) with its own code.
All that was lacking was data so I took a port of Sqlite and adapted it to run on all three platforms (with a single code base using IsolatedStorage)
The http://PasswordMgr.CodePlex.com currently has a functional login screen (panaroma for the phone) which loads "on-demand" a PasswordManager module after a successful login. The
application is a work in progress however the frameworks are essentially completed and appear to be stable.