The routes will have to be flown by the B744ER. Great Circle distances SYD-DFW 8578mi & DFW-BNE 8303mi (the tracks go over the Baja Peninsular and Mexico). The headwinds on the way back obviously dictate BNE in lieu of SYD. It's probably in QF's interest to develop another port as a hub and geographically BNE is the obvious choice. I suspect that they may leave P class fitted to the ER's for this route as it is aimed at Business traffic with AA connections (DFW is AA's main hub).