Wildfire allows to implement a custom UserProvider which is great for integration with complex systems. Looking at the code (which is quite clean and pretty ) I see that UserProvider interface methods deal with User class object. I think having User as an interface may give a flexibility of implementing custom User objects. For example, loading user properties at once from existing database tables would significantly help in integration with existing DB. More than this, user properties not always come from a database but can be loaded dynamically from an app server.
Perhaps I’‘m going in totally wrong direction but I didn’'t find any other way of integrating Wildfire and existing users without very complex replication of a user profile data to the Wildfire DB. Please correct me if I wrong.