The UI for WP7 isn’t actually written in Silverlight (even though devs will be using Silverlight for their apps). So when it comes to panoramic applications, developers still have some work to do on their own and MS has yet to provide a template. Aimee Gurl has demonstrated a way to create a panoramic application and shared her method. She’s shared the code and the library so if you’re a dev you may want to take a look and contribute. She’ also provided a video to show the finished product.