I remember what Yahoo! was originally like: a nice, hierarchical categorization of websites. That was great when there were 1,000 websites. Maybe even okay for 10,000.

Google quickly became an obviously superior approach.

Back when Yahoo! was a categorized directory of sites, my computer had probably 1GB of storage. I didn't have a digital camera or many thousands of email messages. I didn't have as many documents that I either created myself or was given by someone else. I didn't have ebooks. Or mp3 files.

The hierarchy that we have is not necessarily a given and even if it exists on disk, the UI metaphor does not need to be tied to that paradigm. Perhaps there is a better way for the things we do today?

I think the central problem is that few userspace programs get as much engineering and tooling thrown at them as the filesystems. Itunes and similar apps which implement their own abstractions for organizing content have always trailed the filesystem for me in the following aspects

a. Hard to access the data outside the single ui

b. Performance of data import / export trails raw folders / file systems

c. Hard to figure out how to atomically backup the content in an incremental way.

d. No programmatic access.

Perhaps, but I think the answer lies more in backend tweaks than a UI/UX overhaul. File/folder tagging, for example, could integrate easily into existing UI paradigms without having to overhaul (or remove) the files/folders analogy. I agree that dealing with folders gets too complicated above a certain threshold, but to me that signals a need for additional (thoughtful) tooling.