In Seam 2.0.0.BETA1 (from CVS) I acquired a jbpm context from:
@In private JbpmContext jbpmContext;
Session session = jbpmContext.getSession(); session.createQuery("select t from TaskInstance").list();
Session session = jbpmContext.getSession(); session.createQuery("select t from org.jbpm.taskmgmt.exe.TaskInstance").list();