A Non-Player Character should use the same things that a player would use. Perception: Vision and Hearing. Those two things are what you will use first and foremost as a player in your environment. If you want to make an intelligent AI, you must always have those 2 things in mind. For example in Assassin's Creed, the archers on the rooftops can hear your footsteps as you run up behind them whereas if you walk slowly behind them they will not notice you as easily until you are on top of them. Sight used to be a problem where an NPC would turn around 180 degrees to look at me when I am no where near it. For a player, at this time of technology you will only get the Sound and Vision from your television so the AI must have the same limitations as the player. Until technology gets to the stage of touch, taste and smell, developers should look to perfecting vision and hearing as well as they can.

The wii populated motion gaming. The ps3 will have the Move. The ps3 will also have 3d gaming... The xbox 360 has the kinect... with no buttons... with no REAL titles released with it... I think we have a new winner.