"858,000 homes have solar PV panels with an installed capacity of just under 2 gigawatts"According to the story in the SMH, with current rates of uptake, we'll hit the million mark in the middle of 2013, by which time over 10% of homes will have rooftop solar panels (read more here).
Also, last week saw the switch flicked on Australia's first "utility scale" solar farm/ power plant in WA. It's just 10 Mw, but with the price of solar panels still decreasing hopefully it will be the first of many.