No they are not. Java is used to serve millions of web pages per second all over the planet. The #1 use of Java is on the server. Applets have been seeing a small comeback, but their use nowhere near dominates the Java market share.
I have browsed to the Slashdot page many times over the years, but just now set up an account with the site. I am hoping to become a better slashdotter, and become more informed about the online world in general.