Oliver, the figure I quoted was the lost revenue only, with no additional cost. ExXB is correct, aside oneworld partners who will, other arlines need not accept face value, however I presume most reroutings will have been done with oW partners CX/JL/AA.
The 700 pax is twice the capacity, it is not only SYD departing passengers who will need to be accomodated or re-routed, but also the passengers on the DFW end. So I assumed a load of 350 each way.