Chapter 4 of Paul Levinson's New New Media focuses on Wikipedia, the online encyclopedia teachers seem to hate most. I suprisingly found the debate over the use and reliability less interesting than the question Levinson asks of "Does Wikipedia make libraries unnecessary?" The answer from the book seems to be, "Not yet."
However, I would have focused on how it isn't Wikipedia making the case against books, but the internet. There is an increasing availability for entire books, excerpts, and information from books online. Teachers are copying things on to Electronic Reserve for students to read on the computer or print out instead of buying the books, and Google and search engines are encyclopedias themselves. I agree that books aren't in danger, and they very well may never be, but it isn't Wikipedia that is their problem,