Here are my remarks and questions:
1.) Will jBPM 5.0 be based upon jBPM 4.x? You mention the PVM and the native BPMN 2.0-implementation. So I assume it will be. Am I right?
2.) What's the reason for replacing the task management with WS-Human Task? The task life cycle model? Will this be implemented as a webservice as most of the other vendors do or will you supply a java implementation using the same model? You are stating that the engine will continue to be embeddable so I hope this will be a java implementation of the task life cycle model.
3.) Will JBoss ESB be an optional component? I am thinking of embeddability again. Why use an ESB when you don't need one? One of the strengths of jBPM IMHO is the small footprint.