Just stumble over this while shopping for my holiday end of October. There are other decent deals for domestic and international as well.
Looks like there's an across the board sales for the same period regardless where you starting your journey from.
Sales period: mid Jul 2012 - mid Sep 2012 / mid Oct 2012 - mid Dec 2012. Exact periods depends on routes.
What to do in Singapore? This: http://www.greatsingaporesale.com.sg
Other deals spotted:
Perth - Bali : $164.71
Perth - Sydney/Melbourne and vice versa: $238