BPMN 2.0 introduces the multi-instance loop characteristic for activities. The expr attribute is similar to the completionCondition (this is what I meant in my comment on JBPM-2414), could the implementation also include support for the isSequential flag that controls sequential or parallel execution of the activity instances?
Also can the ability to initiate additional activity instances be supported? This is described in workflow pattern 36 (http://www.workflowpatterns.com/patterns/control/new/wcp36.php). Could this be implemented with an event listener (<on event="end">) added to the foreach? For example: Three contracts are scheduled for drafting, during the execution of one of these activities an additional contract draft is deemed necessary, this is added by the event listener before the completeCondition expression is evaluated.
The current patch in JBPM-2414 supports only multiple task instances, it would be great if your solution could support sub-processes.