I've been intrigued with the idea of action objects seen at the LVRUG podium app and have been thinking how these objects can replace controllers altogether. The more I think about it, I think these classes can replace both controllers and routing if they were namespaced and inherited in a standardized way.
Take the example from the podium app (as of 4/30/2014):
module Topics
class DisplayTopics
attr_defaultable :reader_factory, -> { Repositories::Reads::ReadTopics }
def call(&block)