Niner since 2012
@nanderto: I just found this post, about half way down is the topic "Composition provider for ASP.NET MVC" which explains that the interfaces need to be in the Parts folder.
Wow, I like magic as much as the next guy, but can any one point me to where this is all getting wired up? I dont see any configuration in Web config, or anything in Global.asax to wire anything up. Where is all of this hidden?