I thought I heard that if you lodged a tax return last year, you were eligible, but then I've read somewhere else that you had to be getting a Centrelink payment to receive it (which I don't.)
Also, my husband thinks it goes on our combined income, but I earn much less than him a year, does anyone know who exactly is eligible?
There are two lots of payments. One from Centrelink and one from the ATO. The Centrelink one is a $900 payment for single income families and $950 for each school aged child if you receive FTB A and FTB B.
These payments should have been receive by 20th March.

The ATO payment is completely seperate and has nothing to do with Centrelink. It is paid to anyone who has lodged a 07/08 tax return and earned less than $100000. It is also a $900 payment. This payment starts rolling out from 6th April for 6 weeks from that date. People who have lodged their tax returns get paid first.

That's how Centrelink explained it to me, because I was confused as well with the two lots of $900.

I hope this helps.
OMG this question must have been asked 1000 times..

The payments for children at school and Single income families have already gone out.

The second lot of payments happen in april and will be paid by the taxation department. Follow this link for details.

http://www.ato.gov.au/corporate/content.asp?doc=/content/00178930.htm&page=1&H1
Go to centrelink.gov.au then click on Important Messages which includes Household Stimulus Package and who qualifies. If you havn't got paid by now then I would say you do not qualify. Parents with tax benefit Part B, and students I think get it.