Shots leaked to The Daily show what appear to be a Metro flavored build of Microsoft Office for iOS. This particular build is shown running on an iPad. The app's UI is said to be similar to the OneNote app.
The report states that users will be able to edit and create Word, PowerPoint, and Excel files both online and stored locally. Support of any other Office apps is uncertain at this point. The sources also state that there is no work being done on an Android version at this time. They did state that the OneNote app will be updated to share the Metro design.
While this is merely an internal prototype of the app, sources claim that work on the app is complete. This means release could be any time now. We'll merely have to wait for Apple's approval process.
Update: Microsoft has issued a statement saying that the photo revealed by The Daily does not depict any Microsoft software product. In a statement issued to The Verge, they said that "the Daily story is based on rumors and inaccurate speculation."
Source: The Daily