What I would like is that copies seem instant and transparent. Actually, I wouldn't like to think of copying at all. I "copy" (or merely just order) a file to (appear in) some place and it immediately becomes accessible from there. Or I decide to move it back a few seconds later and I can do that.
In reality the computer should manage the low-level copying internally and consider it more like syncing.
I shouldn't have to care about how long something takes or how the kernel will queue the actual copy operations, or whether it copies anything at all but just creates a copy-on-write mapping to the same data. I also shouldn't have to wait for copying: I should be able to just copy something and immediately turn off the computer. The operating system would continue copying the blocks, if necessary, when it's restarted later. All copy operations ought to be logically atomic as well: either a copy is immediately made or it isn't, the physical details of copying and remapping the corresponding blocks shouldn't be any of my concern.
So, an immediate, transaction-based and logically coherent file operations with automatic kernel-level delayed-I/O backend is what I would call the 2000's.
I hope that there already is at least one research O/S somewhere that would do this.