Here's a couple of good reads: Analog Days - The invention and impact of the Moog synthesizer, by Trever Pinch and Frank Trocco. This is a history of the development of the music synthesiser. The subtitle is a little misleading, as ARP, Buchla, EMS get detailed coverage, but as the book identifies, the winner was Moog.
The other book (just out) is Blue Smoke by Chris Bourke, and is the history of New Zealand pop music from 1918 to 1964. This nicely completes the picture, bringing us up to where other texts take over (eg Stranded in Paradise).

OK, it looks like the latency issues have been addressed:

http://createdigitalmusic.com/2010/10/06/going-native-new-pro-tools-hd-native-your-daw-and-low-latency-performance/

At last, Digidesign (now Avid) have seen fit to produce a version of Pro Tools HD that runs on the CPU, rather than requiring DSP farm cards. For several years now the tower Macs have been relatively idle, while the HD cards handle the heavy work.
This should bring the price way down, but rumour has it that a system will still cost US$3,500. Site information states that these are the hardware requirements of the computer (for a Mac): 
Mac Systems
Apple Mac Pro with 1 available PCIe slot
System Software: Mac OS X 10.6.4
Total System RAM: 2GB minimum, more recommended
I would think that a bit more than any old Mac Pro with 2GB RAM would be needed to get the performance of the systems with additional cards. Also, there is no mention of latency. If Digidesign have done their homework and written the code to utilise Core Audio the way JACK does then there will not be any problem. Or have they stuck with the DAE? (horrors).

http://www.avid.com/US/products/Pro-Tools-HD-Native

Nothing to do with surround sound. We are still surrounded by earthquakes, with a magnitude 5.0 two days ago. They are getting less frequent but each big aftershock is a vivid reminder of the big one. Cranes and roadworks are still all around, and I know several people who have had to leave their homes as the buildings are damaged beyond repair. Hopefully it won't be too long before we can forget about all this.