Suresh points out that at this year's FOCS, not a single person wanted printed proceedings, whereas few years ago, a third of the audience would ask for printed version.
I see a similar shift happening with technical books. Purists say that you can't beat the convenience of browsing a real book, but I say that you can't beat the convenience of having access to all your books wherever you go. In the last 6 years, I came across about a hundred technical books I considered interesting enough to get an electronic version of, and since publishers didn't provide electronic versions, this often meant me going to the library and scanning the book myself. One of my first blog posts was on the subject of book scanning.
Today, almost 6 years later, I almost never need to use the scanner, because almost every book I need is already available in electronic form, scanned by someone and circulating freely on the Internet. Increasing number of those illegally circulating books are not even scans, but look like bona fide original electronic versions. Number of legally available electronic versions is also increasing, recent examples I came across are Boyd's Convex Optimization, McCallaugh's Tensor Methods in Statistics and Szeliski's Computer Vision: Algorithms and Applications. Times they are a'changin' !