Though little has been confirmed about the new iPhone, industry analysts are predicting "unprecedented demand" and even "hysteria" for the first new Apple handset in 18 months.
Ovum analyst Tim Renowden said its dominance was particular to Australia.
"Australia is a bit of a strange market in that the iPhone is probably more popular here than in other market around the world," he said.
The iPhone 5 may appear in stores immediately upon its release. It is heavily tipped to feature a dual-core processor, as in the iPad2, a Sony camera, a special wireless charging dock and a Qualcomm near-field communications chip for card payments, something now available at some IGA, 7-Eleven and Woolworths stores.
Mr Fadaghi also predicted a new form for the iPhone5.
He said it needed to address anxieties about iPhone4's "fragility" and antenna problems, and have the latest voice recognition.
There was an outside chance of support for faster phone networks, such as Telstra's 4G.
"There's also a trend towards bigger screen sizes, which I don't think Apple can ignore," he said.
Apple's new iPhone will face plenty of competition. Google plans to launch a smartphone with new software on October 12, Nokia will launch its first button-free touchscreen phone, the N9, this month.
Optus recently cut the price of the 10 million-selling Samsung Galaxy S II.