This blog post was authored by Matthias Shapiro, a technical evangelist at Microsoft.
The cornerstone app architecture for Windows Phone development is the MVVM (Model-View-ViewModel) design pattern. In this video, Matthias Shapiro demonstrates the basic structure of a Windows Phone MVVM app. He shows how you can build robust and flexible MVVM apps for the phone that take advantage of data binding, commanding, and presentation logic (ViewModel) portability. For more information, see Practical MVVM For Windows Phone on Channel 9.