Tim, here is a sample usage of foreach activity:
<foreach in="#{actors}" name="foreach1" var="item">
<transition name="to task1" to="task1"/>
</foreach>
<task name="task1">
<transition name="to join1" to="join1"/>
</task>
<join name="join1">
</join>
Please note that between foreach and join activities there can be any type of activity, including subprocess.
If it comes to designer support for this, I am working on it. Just while ago I supplied a patch for this for a review. Let's keep our fingers crossed that it will make to to next release.
I will try to find some more time to work on pending issues of GPD to have something released together with jBPM 4.4