Exactly - how much information can be inferred from the file and path alone - in a lot of my cases (for very personal files), quite a lot.
If Dropbox gets to interpose itself in every file update systemwide, that sounds like it's getting too much of my information. Encrypted/Stego drives don't matter - once you open it up to the system, Dropbox sees when you touch it.
All I can gather from this discussion is that I'm glad I'm not using Windows and Dropbox together.
This is, by design, a fucking huge defect of the underlying system calls.
Give the OS a list of folders to watch. Dropbox should not even get a callback for a file it's not is supposed to watch.