If you still have to deal with Microsoft Office files everyday on your Chrome OS Device, you can start to breathe: Chrome OS users can now experiment with editing Microsoft Excel and Word files.

Yes! All you need is to be on Dev Channel and enable the obscure chrome://flags/#enable-quick-office-editing flag. Then, you're good to go ;) 
Obviously, this is the very beginning and it might be a little bit buggy. Therefore, I would recommend you fill quickoffice bugs at this custom URL http://goo.gl/VsGHL and attach your office files (if you can) in order to quickly improve it.

Source: http://codereview.chromium.org/15703018/
Editing Microsoft Office files in Chrome OS
2 Photos - View album
Shared publiclyView activity