Microsoft is a software and services company. So the announcement that Xbox games would see action on other platforms ranging from iPhone to Android should not be a surprise. Having the right strategy is important though. Case in point: Office. By offering the ability for Office 365 subscribers to include the iPhone amongst their authorized devices, Microsoft can offer free apps on iPhone and avoid giving a cut of the subscription to Apple.

http://news.msn.com/science-technology/microsoft-to-bring-xbox-pc-games-to-iphone-and-android-phones