DL is no dummy. By this announcement DL is potentially forcing USAir into a higher bid. It might also allow DL to have more access to AA internal information. Finally, if the election brings in a more friendly DOJ in 2013 (when AA will have finished its restructuring activities) DL would already be in a position to easily bid for AA.
But make no mistake, USAir is going to bid for AA once AA completes its restructuring activities. And there will be no shortage of lenders and investment bankers flying to Tempe to kiss the rear of Doug Parker in order to help with financing the deal.