Are there any demo projects (or informative blog posts) for using Prism with Surface (SDK 1 or 2) except for Simon which I have found here.
Is Prism well suited for Surface at all?
If you don't mind, I will answer the second part of the question.
From my humble experience with multi-touch or Surface category of applications, will always require to have fluid UI, very customized UI elements behaviour (Such as Dragging-Dropping, Touch-Hold, Swipe, other gestures that might affect the behaviour of the UI elements), this will weaken your chances trying to use a feature like "UI Composition" as everything will be very dynamic in your application.
Other features of Prism will be usable and it will be quite helpful in tasks such as communication between your usercontrols using "Event Aggregator" for example.