If you've looked at the Auscon site recently you'll see that it's been postponed from May to October. There was a discussion about it on the facebook page so you can see the story there.
As sorry as I am to see the delay, I'm happy that Mark's wife is on the road to recovery and that he's keen to ensure that the convention happens with the preparation necessary for such an event. The two from last year were great and I think there's a good chance for it to continue to improve.
Watch the facebook page for more information as it comes along.