Several changes are being planned for the Australian health insurance system. These include changes to the law to enable insurers to offer discounts to those who quit smoking and get fit, similar to the PruHealth policy in the UK, and the sale of state owned insurer Medibank.
Australia has a first-class healthcare system, called Medicare, but although UK residents on tourist visas will get emergency care under a reciprocal agreement with the UK, anybody living there longer term needs their own healthcare insurance to cover significant in-patient medical costs.
If you are planning to move to Australia, there is a catch. Most Australian insurers will not accept you as a domestic customer until you have been in the country for at least a year, so you will need an international health insurance policy for that period