It's probably more accurate to say that JAXB provides functionality similar to JiBX/Castor/XStream (and Smooks Javabeans ;-) ) i.e. they're Java/XML binding frameworks.
JAXBIntros allows you to use JAXB with an unannotated and fixed Java Object Model i.e. is already written without the JAXB annotations and is unmodifiable (e.g. owned by someone else).
No plans for tooling at the moment.