Java 6 Update 10 to the rescue
There is a new Java JRE/browser plugin coming which solves all the traditional deployment issues of applets - speed, download ease/size etc. The install process/time will be similar to that of flash.
JavaFX will be usable once this plugin is available, and it will also make applets not based on JavaFX a viable alternative again. Too bad that so many people who suck tried abusing applets in the old days, but combined with JavaFX and the new plugin, java in the browser will rule again :)
Check out the new plugin here:
http://java.sun.com/developer/technicalArticles/javase/java6u10/index.html#plugin