Technology Improvements
I think that the emerging 24 bit/96khz standard is a move in the right direction. Unfortunately, the consumer audio CD format standard is still 16 bit/44khz for the time being. The next big thing, however, is called DSD, Direct Stream Digital, by Sony (see
http://www.dsdproaudio.com/html/dsd_sacd_explained.html)
By sampling a signal at 2.8 Mhz (2,822,400 per second) using only one bit (On/Off), the audible result is virtually indistinguishable from analog, and the capacity is increased to 4.7 GB for the same physical size disc. The dynamic range is also increased to beyond 120db.