Absolutely agree re online HD libraries. The problem is there are so many firms that need to change their models for this to happen. It ought to be here now given the capabilities of the technologies. But I know from first hand experience those that have dominated the existing value chains that are converging are more frightened than excited by the possibilities.
In one of your earlier posts, and I may have misinterpreted it, you made a reference to pro audio software interfaces. I am aware of a lot of the hardware. For example, I am aware of the Lynx card, but not so much aware of the software you might put on the computer to take full advantage of it. For example, digital crossover software to make use of the computing power and all those output channels - I am a real convert to active speakers.
I usually rip music to FLAC, as my preferred storage standard. I then convert to AIFF 24/96, and play those, keeping two copies of the FLACs as a backup. This is probably a sign that I still haven't converted my thinking over to the Mac world. I inherently don't like proprietary models when an open model of equivalent quality is available, but it is not entirely rational - ALAC files can be readily turned into an open format without loss at any time.
I keep looking at the DCS stuff but have never taken the plunge. Right now the top USB stuff sounds better to me than the ethernet stuff, but I can't help feeling ethernet will become the dominant transmission standard for anything. It is a steamroller with a lot of momentum and has all the attributes one would want. The reason why USB is dominating is that the R&D to get it to perform is so much less and audio firms are small. In the end, the standard that wins is the one that attracts the R&D, not the 'better' technology, so maybe the start USB is getting will be unassailable in the audio world. Both Firewire and ethernet are harder for small audio firms to develop for.
I was originally very resistant to Amarra. I didn't like spending that much on software, there was little info on how it worked and getting support seemed to be a bit of a lottery. But with all the tweaks I now accept as being part of the recipe for great computer audio today, Amarra does something that none of the others quite do, and so I now consider it to be essential - for how long, though, is the big question - as you say.