A game world that changes while I'm offline depending on other players' actions is actually the opposite of what I call immersive. If I want to play in such a world I leave the house, thank you very much.
I like the other idea, though, of the A.I. adapting to our playstyles. The only difficulty will be how to tell it what of the things I'm doing ingame is actually my gameplay. I have a story save that I use solely to illustrate a story I'm making up, not to play the game. In that story save I use cheats that I'd never use in real gameplay (like freezing needs for everyone and adjusting relationships up and down as needed). There needs to be a method to exclude certain sessions from factoring into the user preferences data.