Sun have an article on their site summarizing all the new features included in their (long titled) Sun Java App Server Platform Edition 9, which is built on the Glassfish community project to build a Java EE 5 server.
The main technologies in EE5 include:
- Enterprise JavaBeans (EJB) 3.0, including a new Persistence API
- JavaServer Faces 1.2 Technology
- Web Services Metadata for the Java Platform 1.0
- Java API for XML-Based Web Services (JAX-WS) 2.0
- Java Architecture for XML Binding (JAXB) 2.0
- Streaming API for XML (StAX) 1.0