Would this approach allow for some default action behavior? For instance, allowing the user to specify an alternate response location for the action's result. I think basic functionality like that should be included in all actions by default, rather than having to rely on each action's developer re-inventing the wheel every time.
See https://jira.jboss.org/jira/browse/JBESB-3313 for more on the above.
I also agree that this approach to action development, along with possibly one or two others that provide the same level of abstraction from the way messages and action configuration are implemented within the ESB, would need to be enforced as the standard methods for creating actions. Legacy actions would also need to be converted to use this approach so that issues like missing basic bahavior doesn't negatively affect future development.