At the moment I'm developing a web based application using Silverlight 3.0. For the business rules I'm looking for a rules engine that's both easy to use for me and my users, which will work with SL3. Is something like that available out of the box or will I need to roll my own?

I've Googled and looked around the various code sites (Codeplex, Code Project etc), but didn't see anything that suits my needs.

I did also have a good long look at NxBRE, but it's Rules syntax is too complex for 'dummy' users.