Eitan Suez gave a great presentation on JiBX. He had great slides for reference, but spent the session time demonstrating the use with real, from-scratch examples. He only returned to the slides for some strong conceptual presentations, such as the weaving of XML and Java references together into a mapping file.
JiBX itself looks slick, with a simple API (al Hibernate) and strong performance optimizations. Bytecode modification still bothers me since you can't select bindings at runtime, though, but it might be a good choice for scenarios such as Atom API implementations. It also got me thinking about XPP.