After a continous publishing history spanning longer than that of the United States of America, the most respected encyclopedia in the English language, Encyclopaedia Britannica, has halted production on its print volumes. The general reference par excellence, first published in 1768 in Scotland, will now only be available online and on electronic media.
When I first arrived in the U.S. as a kid, English encyclopedias fascinated me, because there were simply nothing comparable in the Mandarin language. Of all the sets available in the library, Britannica stood out for its wealth of content and innovative knowledge structure (the famous micropaedia-macropaedia-propaedia divisions). Compared to Britannica, World Book seemed terribly superficial in content, Books of Knowledge and Comptons simply juvenile, and Encyclopedia Americana lacking visual appeal (like color).
As much as I use Wikipedia these days for quick information, I can only hope that, even without the print editions, authoratative and more trustworthy reference sources such as Encyclopaedia Britannica will stay around for the long run.