Haven't checked this out... Netica is Bayesian network middleware :http://www.norsys.com/netica-j.html?popup
There is a free version available and is only limited by net size. The licensing fee is not bad too..
fuzzy FSMs (Simbionic) are certainly very useful though for particular genres of games like FPS. It would be neat to combine the FuSM technique with Bayesian networks to possibly resolve the fuzzy part or switch between different FSM graphs.
Check out the Netica API and report back..
I'd be interested to hear your view on it.