With the update, the execution model of Windows Phone will be improved. In particular, a new "Dormant" state will be added to the application life cycle. The way this works is that when the user navigates away from your application, instead of tombstoning it right away, it is suspended in a way that preserves the whole application state intact in memory. The advantage of this is that you do not need to restore this state when the user returns to your application. Only if the user continues to work with the phone and the operating system eventually gets into the situation that it needs to free resources (memory) to guarantee a great user experience for a newly started or the currently running application, your application will be tombstoned.