The current MVC framework provided by Liferay through MVCPortlet.java supports to have ActionCommand.java. Those ActionCommand classes can be OSGi components that are registered and are executed for both actionURLs and resourceURLs.
This is limiting because developers should be able to register a ActionCommand for a actionURL and other ActionCommand for a resourceURL using the same command.name for both.
Besides supporting Action and Resource we should also include support to handle renderURLs because currently the MVCPortlet framework only allows to do redirect to a specific JSP using the mvcPath parameter. Developers should also be able to register a particular Action for renderURLs so the render method of those actions are executed.