Today Microsoft Office for Android is available for 365 subscribers. It works just like the recently released iOS app where you have access to all of your office files either local or in the cloud (via SkyDrive or SharePoint). You can view, edit and create right from the app and save it to the cloud for later use.
Initial impressions are it is a very easy way to get things starting for a document, or to quickly edit something on the fly. I don't see kids writing term papers with it...yet, but they could be finishing them up before a quick print in the computer lab before class. The best part about the excel is that all the formulas are there, ready to be used. The interface is simple to use, and once you get used to how to format, it will be a sinch to start and edit files.
If you have Android 4.0 or higher on your phone (sorry, tablets aren't supported yet...damn) you can grab it today in the Google Play Store.