I believe the hibernate example app and new jpa example app both demonstrate seam without embedded ejb3.
Right. And you *can* use the existing backend. You need:
Needed: A JSF VariableResolver so that spring (or whatever) components can be injected into seam components.
Recommended: A spring factory of whatever to let you inject a Seam-managed persistence context (Hibernate session or EntityManager) into your existing DAOs.
I guess this is a frequent enough request that we should build a package with this stuff in it.