That's actually fucked up. To spring that "feature" out of no where and then make it not optional, is a very bad move. I know some corporate clients in the medical industry that have used Dropbox for company docs and I imagine that will be going away soon.
I wrote a comment before fully reading the article. Its hidden not disabled. I still don't like that though and I still think the corporate clients I know use Dropbox should move away from it.