What is the current method of implementing the joined-subclass structure with FluentNHibernate? By "current", I mean by not using deprecated methods such as JoinedSubClass or AddPart.
Thanks!
The recommended way to map a joined-subclass is to inherit from SubclassMap much in the same way you inherit from ClassMap for your non-subclass entities.
It's described in the fluent mapping subclasses section on the wiki. For automapping please refer to Automapping Inheritance.