I recently added the ability to display more information on model validation messages (i.e. the fully qualified location of the element), this included adding a method to metafacade base called "getValidationOwner" which returns the owner of the current metafacade, this needs to implemented in the dynamic metafacade elements (i.e. action states, etc).
Wouter, I figured you would be faster at implementing these since you probably know how to retrieve the owners of these elements. Let me know if you're not sure what I mean, take a look at AttributeFacade.getValidationOwner() for an example. I think its important that we get these done before the release since it makes the validation errors much easier to find.