I've heard some of the programmers here at PW talk about wanting NPCs that go beyond the basic scripted variety, and that actually plan and carry out their day to day activities based on their needs. I just recently came across the web site
http://www.ai-center.com/ which contains some neat info on projects that were intended to create such intelligent AI agent behavior. I would especially check out the "Online Documentation" and "Publications" sections under the "Excalibur" project. It's a good reference for some of the difficult problems in the field of autonomous agent goal-making/planning!