Dropbox has announced that it is partnering with Microsoft to let MS Office users access its service from within the Office apps, and allowing its users to edit Office files from their Dropbox mobile app. Users will be able to sync changes across devices and any edit they make will automatically be saved to their Dropbox account. The files created using this integration of Office and Dropbox could be stored and shared via Dropbox links like any other Dropbox files. As of now, this integration is only applicable to MS Office for Desktop, though according to the official announcement, Dropbox for Business customers with Office 365 licenses will soon be able to take advantage of these new features.
The announcement, made in the form of a blog post over here, does not mention anything about the financials related to this partnership, or which one of the companies approached the other.