I feel that "business people writing requirements": rules engines::AI: lisp. Right now, it is just a gut feel, though.

Basically. I love rules engines. I think I just tried to do too much magic with them on my first encounter.

I'm curious too - particularly horizontally-scalable distributed rules engines. I realize that might be contradictory since the Rete algorithm scales by throwing memory at it, but what if you want to throw more facts at an expert system than you can reasonably put in one server?