Amazon won't win in the streaming / file space unless something changes.
Those eggheads over at YouTube/TiVo/Apple/Amazon/Microsoft surely must be working on something like this. I mean, how else do any of them justify their salaries?
Better to say that the physical medium is no longer the only existing medium. Where they once dominated, now they'll become niche like most mediums do once they're past cutting-edge. But antique suggests something that's over and done with, and incapable of advancing. On the contrary, I think that physical media will continue to innovate.
HD-DVD/DVD-Audio sound decidedly better than CD/vinyl assuming you have a sound system high end enough for it to matter. There's nothing inherently better about analog, unless you're talking about copies of the original analog master tapes. (There was a company selling a subscription to a service where you would get copies of analog reel-to-reel tapes)