Well you can pre-register here. You must have a valid email address, so that's the down side, the get your email address to send stuff too. So check the fine print at the bottom and deselect that the exhibitors can bulk email you.
Would you like us to release your email address to all exhibitors after the expo - for their use only - so that you can be kept up to date with the latest developments?
and finally note
Please note that by handing over your visitor badge to an exhibitor at the expo for further details means that you are consenting to receiving information from that exhibitor only.
Having said all that I've preregistered.
There are further detail in liftouts in both The Age and Herald Sun Today(Thursday). Also I'm told its being advertised on TV as well, so expect a crowd.