If they're trying to solve server load issues rather than "why don't it act like WoW" issues, AFK kick takes into account load on the particular zone you're in and boots (faster) if it's strained.
It's probably something a lot dumber like counting SixAxis jitters when you walk by as activity, though.
It's probably something a lot dumber like counting SixAxis jitters when you walk by as activity, though.