Here's an interesting perspective from one of my close colleagues:
For years BA has struggled to convince that it is ‘the’ international airline of choice. From a market standpoint the view has long been that the airlines higher margin North Atlantic routes are its major strength and the rest of the international route based structure comes close behind. Achieving a deal with an airline such as Qantas would in my view do nothing but enhance the strategic potential of both airlines and give them a commanding position against the fast rising star airline in the Mid and Far East. Eventually, it is also my belief that when the time comes that some kind of deal with American Airlines emerges that can meet with international regulatory concerns this really could become a very formidable international airline.
Link