I guess the days of the "red books" are over. Want to see what the future of LCSH might look like? Take a look at lcsh.info:
This is an experimental service that makes the Library of Congress Subject Headings available as linked-data using the SKOS vocabulary. The goal of lcsh.info is to encourage experimentation and use of LCSH on the web with the hopes of informing a similar effort at the Library of Congress to make a continually updated version available. More information about the Linked Data effort can be found on the W3C Wiki. [emphasis mine]
Nathan, thanks for reminding me about this a month ago :) Talk about slow blogging!