You don’t keep your e-mail on your file system, right? The app manages it. And that was the breakthrough, as an example, in iTunes. You don’t keep your music in the file system, that would be crazy. You keep it in this app that knows about music and knows how to find things in lots of different ways. Same with photos: we’ve got an app that knows all about photos. And these apps manage their own file storage.
You can shuffle the parts around, and you still have the same problem. The data ultimately is organized in a hierarchy. If you can visualize that hierarchy, and provide interactions that make sense to edit and view that hierarchy, there’s no reason the same browser shouldn’t be used for all types of data. It does not have to be a “wall.” All your stuff ends up inter-relating anyway. Do you use the emailer to send music files? Yes of course. Do you use a text editor to write about the podcast you just recorded? Yes. So why have 20 mediocre tools when what you need is one really great one.
iTunes as a view on top of the filesystem makes sense. The iOS/iCloud view of a future with no shared state or messaging seems like a dead end to me. I don’t think it will work to pre-determine all the interactions that people will want.