Just to add to what Esteban said if I may :)
We are in the process of moving the jBPM Designer code to the jBPM github: https://github.com/droolsjbpm/jbpm. This should be done very soon.
Designer is not a personal project that lives in some private repository but is a jBPM component (http://www.jboss.org/jbpm/components/designer) and if I may say the best BPMN2 editor around ;) It does however have independen release cycles from jBPM which will continue after it's moved to the jBPM github. This is important so that we can turn around fixes to you guys as fast as possible (that may be completely unrelated to the jBPM engine). Also, we would be very much pleased to have more of the community play with the Designer code and possibly contribute cool features so feel free to ping me any time on IRC ( http://www.jboss.org/jbpm/irc ) and I'd be glad to get you guys up and running.