Inferencing engine in(cluded) Rebol?

Hi, as most of you know Carl has mentioned an inferencing engine, which might be added to Rebol. I'm currently architecturing a concept for a customer where I'm going to use a seperate rule-engine to decouple the business logic from the application logic. Anyway, I'm more interested in the future support of rule based concepts in Rebol. Did anyone already made some tests or has a short script using rules? Maybe someone from RT can let the rat out of the bag and tell us what is planned. I don't want to start working on such a topic, if it will be available in the near future. Robert