make it so that the npc's fight each other. have it so that you can join a village and help them fight other villages.If notch won't add this into the game then that's fine but SOMEONE at least make this idea into a mod!!! add new buildings like barracks, training camp etc.
Vendors of course.
Maybe Inns could be built in towns and Inn Keepers?
Maybe a person you could hire and they would either do something for you or follow you and help you.
Quest Givers.
Currency?
With the hiring idea maybe you pay them and they get you certain things for money, ex: 30 wheat for 60 (whatever currency is)
Now feel free to post your thoughts!