Interesting article on Titanfall's cloud usage, and some insight as to why the cries of "But developers can just use Amazon or Google!" are trying to answer the wrong question.
So it looks like if you are building an XBox game, you get preferential pricing on the Azure cloud. This will be very hard for developers to match with Amazon EC or Google, because those companies can't offset the price with licensing revenues.
http://www.respawn.com/news/lets-talk-about-the-xbox-live-cloud/
It would be more interesting if dedicated servers were a new concept.