Here's another good example of Ms using cloud for halo gaming, wouldn't be surprised if this became the api for devs for xb1 cloud ... http://www.zdnet.com/microsofts-orleans-cloud-programming-model-gets-a-halo-test-drive-7000009300/
Did you read the article? It talks of use of the cloud for production of the game. That sounds like rendering videos, etc. Not actually doing anything of note during an actual running match.