According to BGR‘s source(a so-called "reliable source") Microsoft is planning to release a version of Office in November for the iPad as well as Android tablets.
Our source has seen Microsoft Office running on an iPad first-hand and has said that it looks almost identical to the previous leak from The Daily a few months back, despite the fact that Microsoft flat out denied that the app was authentic. It is also plausible that Microsoft Office will be coming to the iPhone and iPod touch rather than only the iPad, as we're told the loading screen in the app clearly said "Office for iOS" and not just iPad.
The iPad’s been out since 2010, and has yet to receive an official version of Office from Microsoft. (Although Microsoft did make a version of OneNote.) There are alternatives to Microsoft Office: Apple offers Pages, Numbers, and Keynote as alternatives to Word, Excel, and PowerPoint (although these iWork apps are separate purchases which cost $9.99 each); there’s also Evernote, which can handle basic document formatting and is available for free; you can get Documents To Go if you really miss your Palm Treo. But those alternatives only offer basic compatibility for office documents.
In February, The Daily had published a photo of Microsoft Office running on the iPad and said that it will be available in the App Store soon. But soon it was denied by Microsoft, although The Daily responded by posting yet another photo of the app.
November will prove it is a rumor or not.