Here is the text of a response I received from the Australian Gov, Department of Immigration and Border Protection:
Thank you for your correspondence of 7 August 2017 to the Minister for Immigration and Border Protection, the Hon Peter Dutton MP, concerning Australia's participation in the US Global Entry Program (GEP) . The Minister appreciates the time you have taken to bring this matter to his attention and has asked that I reply on his behalf.
The Department of Immigration and Border Protection (the Department) is considering how to participate in the GEP and is in early discussions with the US Department of Homeland Security. As a part of our considerations on deciding whether to join the US GEP, we will be weighing up the benefits to the traveller against other implications, such as resourcing and costs.
Thank you for raising this matter with the Minister. Yours sincerely