2009 has not been kind to Oz, unemployment is over 6% for the first time in years. Sydney has always had the majority of IT jobs in the country, but has also has had the worst of recent layoffs. Melbourne was a distant second followed by Brisbane.
Canberra is a lifestyle choice. Cold (for Oz) Winters, Hot Summers, but working for the Federal Government has a lot of benefits.
There are virtually no IT jobs outside the capital cities. Gold Coast has rapid growth but a dearth of IT jobs, but has the best beaches. Other cities the best bet is the Local council offices or universities, but you have to be extremely lucky to even get an interview.
Some areas like the NSW North Coast have a high concentration of people with IT experience and virtually no IT jobs. A lot of IT folks in the bush make money opening a computer shop. People like to take their computers locally for service and buy them locally. It's not great money and there's no guarantee but it's a good choice for smaller centres.