> if by unhappy chance it turns out that some of the quantum details of the brain's state are important to the mind, then it's possible we may simply never be able to copy a person. Let us hope that is not the case.

I would hope that that is indeed the case...

For people who are into anime, there is a very nice one about this issue called Kaiba [1] that envisions a future where everyone is freely able to modify their memories and swap them across bodies.

[1] http://myanimelist.net/anime/3701/Kaiba