Australia has an internet penetration of 70.7% (14,663,622 users) according to Nielsen (via internetworldstats.com). This is slightly higher than North America (68.1%) but below Malta (78.1%). This is a measure of people who have access to the web… and probably not a true indication of how many people actually use the internet regularly. Given that the number of broadband users is 1,300,359 there are still a lot of people who have dial-up to check their email once a month.
On a semi-related note, Whirlpool.net.au is having their annual Australian Broadband Survey, you can give your view on the state of broadband in Australia by going to http://whirlpool.net.au/survey/. The survey will take around 10 minutes to complete.