BlueJ is an IDE designed for beginners - it's not a professional level IDE, it's one designed to make the process of learning Java as effective as possible for beginners. It can still be used for more advanced programs and tasks, but most people migrate away to something like Netbeans or Eclipse after they become competent.
Nothing that I know of for Eclipse, but there is a Netbeans plugin out there. I'm not sure if this works with later versions of Netbeans however, the version quoted there is 6.5.
