Eclipse 3.1 M4 is available. One of the new features is an Ant debugger. Ant is a simplified make tool providing common build commands in XML files.
Living in a Smalltalk world you dont need such a beast. You typically automate builds by just writing Smalltalk classes, methods and expressions. So you dont have to switch the tool and technology and you can use the normal Smalltalk debugger to debug. So you have a completely different Experience then working in Java.