In some ways, this feels like i've been full circle. I'm back to writing Antlr grammars. Antlr 3.2's tree filters are wickedly cool, and Terence Parr's Language Implementation Patterns is thoroughly hurting my noodle. It's a damn fine read, if you enjoy LL(*) and syntactic predicates.
One of the things I am playing with at the moment is stuffing Antlr generated parsers inside of web browsers using Google's GWT. It opens a wild vista of new potentials, of being able to edit and hack seriously complicated models inside a browser. Revenge of the nerds, web2.0 style.