Hi,

I created open-source "Bean Validation in JAXB" specification and reference implementation. It is a part of EclipseLink MOXy solution which provides JAXB 2.0. It uses Hibernate Validator as its default BV provider.
It is a fully-functionable integration of BV with JAXB. All main areas are covered, including marshalling, unmarshalling, XJC (Plugin) and schema generation. User-specific annotations are also supported.

More information at: https://wiki.eclipse.org/EclipseLink/Examples/MOXy/BVinJAXB