[jmulder]

Folders or tags are hard in the sense that both of them require a user to think about organisation, when in reality any of them just wants to find the file 'magically' where they last left it and do stuff with it. In most cases this is in some application or (in my opinion still a temporary stop gap) a one level deep file system.

The applications itself will serve the needed context or metadata (type of document, last modified time, access/sharing privileges) to find the files you're looking for.