For version 2.2, we're finally implementing inheritance, both for data objects, and for logic objects.
Inheritance for data objects is of course Hibernate's business, and it's a pretty large topic, better left to Hibernate's documentation
Inheritance for logic objects goes hand-in-hand with it, and makes it possible to factor out logic into superclasses, and to mirror the hierarchy of the data. You can declare e.g. your @CurrentBean once and inherit it, or you can redeclare it with the proper type in the subclasses, thereby eliminating the need for a cast.