So from my reading of it, Ryan's project takes a bitcoin payment from the customer, converts it into AUD, then connects to PostBillPay and pays the bill, then send the customer the receipt from PostBillPay.
Bill payments 1.0: Customer -> Biller
Bill payments 2.0: Customer -> PostBillPay -> Biller
Bill payments 3.0: Customer -> BitBillPay -> PostBillPay -> Biller
It's a great idea .. but I imagine if it takes off, AusPost will implement pay-by-bitcoin in their own service.