I was wondering if anybody has documented how best to put a .NET commercial application on the Cloud and being able to charge for its usage.   I assume that porting MS Office to the Cloud has brought a lot of good lessons the Microsoft is willing to share.   This warrants a book or two.

I am not taking about web application here, but rather applications with complexe and real-time user-interfaces and that require fast user response like CAD application or very elaborate video games with full 3D user-interfaces.   It's the type of application that are best executed on the user machine with some parts on the Cloud so as not to allow users to pirate the software.

Let's suppose that the application is built around XNA.   Can we easily put that applicaton on the Cloud and charge users on a per month basis?