- Hibernate Entity Manager, Annotations and Envers are now part of Hibernate Core (so they now have the same release cycles and version numbers, no more compatibility matrix hell).
- Full support of JSR-317 (JPA 2.0). Yeah baby!
- Support of a new second level cache provider (Infinispan which is actually a data grid, pretty interesting).
- Support for JDBC 4.
- And more, see the official announcement.
And for the impatient Maven users, you can get the new artifacts from the JBoss Maven repository.