Java IDEs?

Billy the Mountain asks: "In the startup company I'm in, we just got a new president and she asked us about ways of increasing developer productivity. We develop Java applications, servlets and JSP. I don't use an IDE. I use an enhanced text editor, EditPlus, because I like its color coding of keywords. I guess what I'm asking is what Java IDEs do you use and what features do you like best?" If you were to build a Java IDE from the ground up, what features would you include?