Oh, I forgot. Another good site is http://www.savemymemories.org. It's run by an international imaging association to which most major imaging companies belong. Anything on the site has had to pass muster with a board of imaging scientists.
"Organic dyes" have nothing to do with Technicolor print stability. All films and most colorants (in ink jet, dye transfer, etc.) use organic dyes or organic pigments. What made old Technicolor so stable was that it could produce silver separations of the three primary color records, and it was the silver negatives, which are extremely stable, that can be used to strike new color prints (with their organic dyes). Trouble is, this is a very expensive process. Disney used it for its animated features which it intended to release again and again over many decades. Most studios went for the much less expensive dye originals which are less stable, especially if poorly processed or stored. (New viewing prints can be struck from properly stored master prints.) Modern color movie films are quite stable (science marches on), which is largely why the costly Technicolor separation process gradually disappeared.
Digital systems pose their own problems, of course. There's media obsolescene (8-inch floppies, anyone?), digital integrity (bit drift, etc.), and media integrity (oops, that tape broke again). Much of what keeps archivists busy is deciding protocols for the continuous migration of images from one generation of media to another.
For really good up to date information on image permanence, I recommend the independent, non-profit (unlike Wilhelm) Image Permanence Institute at the Rochester Institute of Technology. They've got some excellent, free downloads on both the basics and the advanced stuff. Wilhelm's book may be free, but it's very old and out of date.
http://www.imagepermanenceinstitute.org/
Back then Wilhelm knew that to get his operation off the ground in Iowa, he had to make a splash, so he attacked the big guy, Kodak. Actually Kodak's films were largely state of the art when they came out, which of course is not nearly as good as everyone's films and papers are today. Many imaging researchers question Wilhelm's methods (he won't let anybody in his laboratory) and he made totally wrong predictions about Epson ink jet prints when they first came out (he overlooked ozone effects). He also overweights the effects of light on image lifetime when over 95% of prints are stored most of the time in the dark, where thermal effects are the actors. None the less, his ratings can be useful if read cautiously. He currently has given a "Best in Class" permanence rating to Kodak's ESP ink jet prints, which when you consider the low cost of Kodak's ink jet catridges (compared to HP, Lexmark, Epson and the rest) makes this a good choice.