That's a great point!  NLP has reached it's shelf life.  It's great, but that doesn't mean it isn't obvious that there will never be a set of patterns that catch fire like the early few that defined the field.  Which makes me think it has less to do with any internal validity of those models, but that they spoke to the zeigeist of the times in a powerful way.  I wonder who will pick up the ball. cindy