I think that the way we're expected to import models into bones is extremely "hacky." I'm trying to circumvent that by creating a JSON-serialized (as opposed to Java-serialized) format that gets exported right out of Max (later, I expect to convert the Max Script to Blender's Python as well). The script is coming along nicely, but I haven't had to create an AnimatedGroup from its product yet, so I don't how long that will take.
To answer your question, I don't think there's a usable new importer (from what I gather, jME3 actually has FEWER importers than 2 to begin with).