I think its greatest use would be in role playing games to create more realistic charecters.
In case you havent heard of it I'll describe it.
Each charecter is assigned an overall personality mood, that is the standard. Than, each event that occures causes a spike in the mood that slowly drifts back to its normal state. The greater the spike the longer it takes for the mood to return to normal. The spikes than move either up, for good mood, and down for bad mood.
It would be interesting to see in roleplaying games because of the depth it would add to the people. You kill an childs mother in the game and rather than just calling the guards or whatever the child actualy gets angry.
For even greater depth, in a 3D polygon design, you could add body language. So, you see a guy walking down the road and you can tell he had a bad day even before you address his charecter.
The only real difficulty I see with this is how much proccessor power it will take.
What do you all think? I'm interested in some feedback because I'm considering using it.