Microsoft plans to release Office series software on iPad and Android based tablets this November. This application's loading screen shows "Office for iOS" on iPad, this may indicate that it may also be compatible with iPhone and iPod Touch.
The Office series software will also be available on Android at the same time. Some details about this application are still unknown, such as price and features.
Last November there was news showed that Microsoft was developing Office for iOS. Microsft also planed to develop newer version of Office for Mac.
On Office for iPad, users can create and edit Word, Excel and PowerPoint files both locally and online. But we still don't know whether it will support other components such as Outlook and Communicator.
Actually Microsoft has developed many applications for iOS, such as OneNote, Bing,SkyDrive,My XBox Live and Kinectimals.
Reference : http://news.csdn.net/a/20120524/2805900.html