I guess this is correct, because the whole idea of the event is to capture the outcome of the assignment.
I don't consider the current implementation beeing correct. I already filed a bug report at http://jira.jboss.com/jira/browse/JBPM-300 but didn't retrieve any response yet.
In my opinion, an AssignmentHandler (configured through assignment="...") should actually perform the assignment. The assignment in turn fires the task-assign event on the configured ActionHandler. This handler definitely should retrieve the information what actor has been assigned.
Maybe I'm missing something. I'd be glad if somebody could enlighten me, if so.
I meant by "this is correct" that the firing of the event should be done following the assignment. So I agree to JBPM-300.