JAXB is licensed under a dual license - CDDL 1.1 and GPL 2.0 with Class-path Exception. That means you can choose which one of the two suits your needs better and use it under those terms.
We use GlassFish Governance Policy, which means we can only accept contributions under the terms of OCA.
Follow @gfmetro (TBD) on Twitter to get JAXB and wider Metro (WSIT, JAX-WS, ...) related updates. See the Metro website at http://metro.java.net to access Metro documentation and release information.
If you run into any issues or have questions, ask at our user forum: users@metro.java.net, or file an issue at one of the issue trackers