There's a really simple solution for the publishers: become the preferred buyer and seller of their own used games. It would offer them another opportunity to interact with their customers, sell them another game, see how long they are playing, and ask them about what they liked and didn't like. Oh, and they'll earn the revenue instead of Gamestop or Amazon.

My favorite 'AI experience' was the first time I encountered the marines in the original Half-Life single-player game. They chattered and moved as a team, they reacted to my grenades, they reacted to being hurt i.e. "man down!", "fall back!". I suspect, however, that level designers deserve the greater part of the credit for making those NPCs look smart (and fun to fight).

A game's systems work together to create an experience--in order for one to shine the others must be well designed, crafted, and integrated. Sometimes fixing a camera, tuning NPC stats, or adding some scripted chatter will do a lot more for the perceived intelligence of the opponent than a more sophisticated AI algorithm.

I think it's easy to lose sight of the ultimate goal (making a fun game) when coding AI, because, let's face it, making brilliant AI is a sexier challenge than paying attention to all the little details the make a level play well. Ironically, one of the problems in game AI these days is how to make the AI a little dumber (but not a lot dumber). It's easy to make a chess AI that will beat most people, but getting one's ass handed to one 30 times in a row is tiring to say the least. On the other hand, an AI that can be beaten handily isn't much fun either.