A couple of new Patterns & Practices guidance papers have been released for Windows Phone. I haven’t read them yet, but they look really interesting. Here are some links for your enjoyment:

• A Case Study for Building Advanced Windows Phone Applications
• Building Testable Windows Phone Applications
• Note: The Microsoft.Practices.Phone.Adapters.Source can be download as NuGet package.
• Developing a Windows Phone Application using the MVVM Pattern