If you're planning on attending Eclipse Forum Europe 2008 held in conjunction with the JAX conference you might want to check out a couple of EclipseLink sessions.
Eclipse Forum Europe April 21-25, Wiesbaden, Germany
Eclipse JPA: EclipseLink and Dali: Shaun Smith, Peter Krogh
Developing with JPA and JAXB: Shaun Smith, Peter Krogh