Anatta and Sunyata: Substantially Different Concepts?

(Did you get the joke?)

Perhaps someone out there with deeper knowledge of the doctrinal subtleties of this can help clear this up for me, but I have to admit that I’m hard pressed to find a big, hairy difference between the two.

Anatta can be interpreted strictly to mean that there is nothing whatsoever that arises in perception that is or is a property of a self, soul, me, etc.  This would be a completely accurate interpretation.  This is also exactly identical to the emptiness of ‘the self’.  So far, so good.  But if we allow a somewhat greater degree of freedom in interpretation, we could say that anatta also applies to all phenomena, not simply the putative self – all things are without their own self-nature (that is, there is nothing that is or is a property of a self of those objects).  How do we know this?  Anicca: if things had their own self-nature, they would not change, now would they?  Which is precisely the evidence brought out to support the supposedly different (and putatively superior) Mahayana doctrine of emptiness.

Now, of course, anatta is (almost?) always used in Theravada parlance to refer to one’s own self, soul, me, ‘I’ (etc.) as a matter of training.  Theravada theory and practice aims to  produce arahants through the clear perception of the emptiness of their own selves – it is not entirely clear whether it follows from this that arahants must therefore have overcome the misperception of inherent existence (or self) in external objects as well.  Regardless, this seems much less different than the sectarian cheerleaders for ‘higher’ yanas seem to suggest – it seems as though Theravadins do not talk about emptiness much because it’s not really relevant to their aims.  Does it boil down to this, or is there a real distinction that I’m missing here?