I have created some new actions; a detour, a variantion on a smooks mapper, and some custom actions we use to integrate with our custom solutions in the ESB.  I wanted to by able to have the editor show my new actions in the new->action menu and then guide the user in the correct configurations for each.  Using the custom action requires them to know the class name, what properties to set, etc which can lead to errors by our integration designers that will be creating the integration flows.   When I'm done, I want to have a plugin that can be installed with the JBoss tools that provides our custom extras in the editor.

I was able to figure out by trial and error that you could do this by creating a new plugin and extending the extension points for the XModel meta information files.   Then it was a matter of figuring out what each thing did in the XModel.  There is one posting on it http://community.jboss.org/wiki/XModelinJBossTools which helped a bit but it would really be useful to understand what each tag does, particularly the ones that drive the dialog editor pages.  Looking at the source code as helped as well.