How would this ruling effect libraries where both the works are available, plus the technology (xerox machines) to duplicate them.
Damn good question....
Of course the RIAA is interested in only recorded music....but there are audio book recordings....
It's generally understood that you DON'T use the library's copier to duplicate an entire book.
It's generally understood that you DO use publicly-accessable shared-directory peer-to-peer software to duplicate an entire file.
There's a difference.
Downloading copyrighted works through P2P file sharing programs was ruled LEGAL under Canadian copyright law a few years ago and the Judge here used that same example of libraries with Xerox machines.