I'm very happy to see design mature from throwing opinionated spitwads at glass to see what sticks to the discipline that it is becoming. It seems like after the Silver Age of gaming in this country, the dedicated designer role disappeared for a while. It wasn't a bad thing, as it forced designers to master other disciplines, to become more technical or more artistic, to gain a more tangible role than the kind that hackers and table-top dungeon masters had. And now, armed with some dangerous knowledge, game design is seizing it's own role again. I think some practices in the past gave pure game design a bad name, but that will change.
In this evolution, I see the next step of it as attuning the plentiful principles of game design into both a science in itself, and a substrate for other sciences. Philosophical taxonomists like Eric Zimmerman and Katie Salen did the former in Rules of Play, finding the core features of what games unique systems. Their book helped game designer know ourselves. My article was a small step towards knowing others. With the science of game design defined, I think we should apply them in context, find our motives and our audiences, and cross-reference the vast knowledge of other fields. As long as games are designed for a player, and that player is human, then all the other realms of science that actively seek to improve human life are relevant.