Also, even though I have a child at home, I never had a book that "broke" - as there's nothing that some glue can't fix. The only real danger for the preservation of books in physical form is fire.
> by centralizing many books to one physical object, you risk losing much more content as you lose that physical object
No, you got it wrong. The far bigger danger is that the eBook reader is a device running on integrated circuits and battery, which will break in only a couple of years and those B&N servers will not be online forever (I would be quite surprised if they are still online in 10 years), it's only a question of when that will happen.
And making this whole thing defective by disallowing people to backup their books however they want is the most evil and stupid thing I've ever seen. DRM is defective by design and no matter how much you try painting this crow, it's still a crow.