I don't really listen to what Georgeson is saying, he's on a giant hype train. I'll wait until they are demoing finished systems.
If grinding mobs is inefficient then you just find the best way to do whatever. If it's exploring, then you can create the most efficient route of running around the map. If it's completing achievements or something, then you're bound to find replicated behavior patterns in NPCs. Once you find a pattern in TIer 1 orcs, it'll probably be in place in Tier 3 orcs. Therefore, you learn your lesson and exploit future events.
These developers aren't gods, we don't have AI or tech to create a fully dynamic world where shit just happens and it's fun. Fun is the key word here. There will be human elements all throughout the design process, especially in content creation and placement. Where there is human elements, you can exploit them.
When I say human elements, I mean things like "this would be fun if I just left it, but I have to tone it down because of XYZ" or "I would love to do this, but I have to gate this content artificially because of subscription monies or content consumption rate or whatever". If SOE can actually write AI to react with everything in the game and have the balls to let it just go nuts and not put any human made barriers on it, it'll be a fun game to play with.