It would be cool to see incredibly rare behaviours, such as if you are going up against a bunch of mercs, wipe the floor with all of them, and round the corner and shove your rifle into the last one's face he'd be like "fair cop mate, I'm out of here". This would only happen every once in a while but it would be a fantastic reward for the player to feel like they can, if they do well enough or play in a certain style, make the AI feel simulated emotions - fear, rage, complacency, etc. So if you snuck through the building and carefully knocked out guys they might not be fearful, but complacent, but if you did the same thing and brutally fucked them all up with knifes, they'd be much more alert but fearful and prone to error.
Personally I don't think this would be hard to simulate, for instance fear would be marked with increased cursing, decreased accuracy, increased error, and a potential for full scale running away. Complacency would mean that guards don't check every corner on their patrol routes, have smaller visual cones, and are slower to react when shit hits the fan. Confidence could be marked by seeking cover less, drastically increased accuracy, and so on.
So yes, whilst in the distant future we could have truly "intelligent" AI which would lead to unpredictable gameplay, we at present have the tools to create enemies that can provide a much richer and more vast array of feedback to the player's behaviour.
"It would be cool to see incredibly rare behaviours"
Working in game design with complex AI, I can tell you that the last thing players ever want is rare behaviors. They tend to think of these things as bugs even if they are simply that, rare behaviors.
Then again, I've been working in game systems where the rare behaviors are sometimes positive and sometimes negative for the player. Given this, the negative ones stand out as "bugs" even if they are not.
Personally I don't think this would be hard to simulate, for instance fear would be marked with increased cursing, decreased accuracy, increased error, and a potential for full scale running away. Complacency would mean that guards don't check every corner on their patrol routes, have smaller visual cones, and are slower to react when shit hits the fan. Confidence could be marked by seeking cover less, drastically increased accuracy, and so on.
So yes, whilst in the distant future we could have truly "intelligent" AI which would lead to unpredictable gameplay, we at present have the tools to create enemies that can provide a much richer and more vast array of feedback to the player's behaviour.