Earlier quoted context omitted.
Mac OS X already has that, but I still would not like to see the filesystem hidden from me. It's just too valuable idea for it to go away and it takes us further away from general computing to turning our computers into appliances owned by our OS vendor.
I think the idea of the parent poster is that there would be no file system (at least not in the sense of a tree hierarchy of directories), just a large database with some SQL like language exposed through the GUI.
See: http://nascent.freeshell.org/programming/TagFS/ https://secure.wikimedia.org/wikipedia/en/wiki/WinFS
and many more.