@dlowan,
I saw Costello say that his greatest achievement was the GST. Wow, what a brilliant career. I change the tax system so it reflected what about 80% of developed nations have - talk about going out on a limb.
Of course it became a cash cow and allowed them to throw money at the states - which hasn't appeared to improve the services the states offer (I'm thinking health in QLD and almost everything in NSW).
He was a perfect match for Howard, a man of small ideas.