This issue is unfortunately blocking our migration from JBoss 4.2.3 to JBoss 6.0.0.Final.
As you can see from my github example / attempt, this is not as easy to do as we would all like to think.
Either you take over complete control over how JPA is handled in your code,
or better, try changing you app to be compatible with AS' Hibernate version.
What's preventing you from using AS' bundled Hibernate?
Hibernate's main interfaces shouldn't change at all? Or JPA1 vs. JPA2?