The problem I have with the Xbox integration is that it's not - it's a separate setup. There are NO games that allow me to switch between the Xbox and my phone, nor is there even any cloud backup. Two examples:
1. ilo milo - cool little game, available on both Windows Phone and Xbox Live Arcade. I bought it on both. It doesn't sync progress. If I sit on the can for an hour plowing through levels on my phone, I don't want to have to play them AGAIN on my Xbox (and yes, they're the exact same levels).
2. Tiger Woods (or any similar character-driven game). Why can't I work on my putting game, or any other skills-based thing on my phone, which then syncs, so when I get on my Xbox to play a tournament, my skills have improved?