The biggest markets are all English speaking or use English as a trade language though. The seller needs to learn the language of the buyer, not the other way round. Who knows, that may change in the future if China opens its markets to foreign companies, but for the foreseeable future English will remain the language of business.
It is a great idea for Australia to integrate more with the surrounding nations however, to better position itself for the future. It's essentially an English/Irish colony state but it can't go on pretending it's not deep in the middle of Southeast Asia.