"Here are three key factors Redmond is trying to balance:
- Microsoft is coming from behind in the phone and tablet space, and has touted Office support as a key selling point for Windows Phone and Surface.
Microsoft Bringing Office to iOS and Android - Ina Fried - Mobile - AllThingsD
- Office needs to remain relevant, and doing so means being on all of the devices its users are running.
- Office, along with Windows, remains a key profit maker for Microsoft and one of the main financial engines it needs to compete in other areas, including search and mobile devices."