I would like to keep shipping Hibernate 4 but also want to see the ability to integrate different persistence providers that are tagged with a version identifier. The AS7 javax.persistence.spi.PersistenceProviderResolver should be able to contain multiple instances of the same provider with different version tags. The packaging of the persistence provider should allow for additional integration classes to be specified (e.g. custom classes for scanning a VFS file url for entities or using jandex for faster annotation scanning). A custom persistence.xml "version" property can be introduced to match the persistence providers version tag.
If we were to do this via "module" packaging, Hibernate 3 could be resolve via a dropped in Hibernate 3 module.