The explanation is not satisfactory. There is plenty of unintuitive stuff crammed into explorer, and junction points are used liberally within Windows. It would be trivial to add say a column in details view (along with the 100's already in there) which is not present by default but can be added by the user. Backup programs use the Windows API and can do whatever they want, it has nothing to do with the shell. This is in fact an excellent reason why so many programs in Windows don't make use of the features in the platform - because the shell is crippled.

Get the TabHistory addon. I usually do a search and then open the result in a new tab. With this addon each new tab/window preserves the history so you can go back and see what you did.

Great ideas and great post. I've said this before, WinFS was supposed to accomplish much of this, esp the part about having having a database backed file store, rich metadata and programmatic access to it. Its a real pity MS decided to scrap it.

I think this could be done more efficiently by writing a file system driver which would hook into NTFS as well as a windows service that would work at organising tags, collections etc in the background. Obviously this is not a trivial task and I'm guessing it would need OS integration to really work well.