I am getting started with Biztalk 2010 for the first time.
I looked at this article (http://www.codeproject.com/KB/biztalk/BRE.aspx) for making a custom action to fire against a condition, but it seems that properties are being used in actions, not conditions. Can an action reference a .NET method which accepts non-primitive types as parameters (e.g. custom classes etc)?
The BizTalk Rules Engine can deal with several types of facts, including plain-old CLR objects, both in condition evaluation as well as actions.
In order to test you policies, through, you will need to create a custom Fact Creator for the specific .Net classes you want to use.
When using .NET objects as facts, please, pay close attention to correctly implementing object identity with the help of the GetHashCode and Equals methods.