Responding off topic. I just made this doc on using Hibernate in TomEE. http://openejb.apache.org/tomee-and-hibernate.html
It's still pretty thin on details, specifically around adding the right jars. It would be absolutely fantastic if you'd be willing update it and add any other notes you think would be useful. Maybe some notes on deleting OpenJPA or any advanced topics. Just click the little blue pencil in the upper right. Very excited about our new website editing feature and hope we can capture some experience from people actually using these various configurations. -David