I came accross this 2001 Extremetech Article on the History of Surround and some of the technical aspects of various formats. I found it informative, if slightly out of date ("generally, sound systems emply a 5.1 configuration..."), but I think most of the info is probably still accurate. I particularly like the section on "Psychoacoutstics". Pretty cool. I'd be interested in hearing other opinions of the info.
http://www.extremetech.com/article2/0,1558,12166,00.asp
