There doesn't seem to be a recent discussion about the virtues of both and I would be interested to see which one comes out best. Currently I use eclipse 3 M6 release, and haven't used netbeans for over a year. I particularly like eclipses ability to refactor, for automatic code generation and being able to follow the method call trees. Any other thoughts?
NetBeans seems to have an advantage in drag and drop GUI creation, but it appears that feature will be coming to Eclipse sooner rather than later. My vote is for IntelliJ IDEA. (I had to throw everyone off.)
Personally I have no need for drag and drop GUIs as all my GUIs consist of handcoded HTML in the form of JSPs and XHTML with copious amounts of CSS I can see where for people working on Swing GUIs Netbeans could have an advantage though any visual environment invites sloppy separation of display and business logic (just double click the button in the editor to add the code for the business logic that goes under it, we've all done it at some point...). Therefore GUI editors need to be used with extreme caution and self discipline!