Comment #14 on issue 177 by pekka.klarck: Listener interface should be able to alter keyword, test and suite status
http://code.google.com/p/robotframework/issues/detail?id=177
Bryan, passing the actual objects to listener methods is possible but has some limitations:
1) It does not work with Java. Or at least it would require a huge amount of work.
2) At the moment the objects don't have stable/documented API. That hopefully will change in RF 2.8.
Assuming there was a stable API, and you were using Python, passing real objects to listeners could allow interesting possibilities for building frameworks on top of Robot. You may want to submit a separate issue about that.
