E-mail certainly isn't a true work flow environment, but that's how I often use it. It's better than file services for sharing individual data. Besides, file service has never been as user-friendly as I've wanted. Of course, file services are still useful. We still need some centralized storage facility from which applications can be staged.
Users can store their personal data files on the file server where they can be backed up.
Still, if any of those client disk backup programs ever really worked, users wouldn't need centralized storage for that either. File service just doesn't fit the way organizations use and share data well enough anymore. It's the old way to share. The new way to share data is becoming increasingly apparent. I believe that conferencing systems, as they extend to full-blown document stores for individual documents will take over the position of file services for most users and uses.