The current Java API has not changed since this post. Progress includes preparations and infrastructure progress simply to get ready for the migration. A study was done together with people from EclipseSource to explore the options of making this move. Each option requires significant work. We have some experiments in mind.
A twist to the approach is presently looking attractive. It is desirable to use EMF only in-memory. The persistence format would human-readable parseable text. An Xtext parser will do the loading and serializing. Significant progress in this regard has occurred with a new action language called MASL. The first structural elements to be persisted as text are the signatures and parameters of the functions and operations.
In both cases, an ecore API would be exposed for the metamodel.
I hope this helps.