Hi Rob,
The sailing scene is alive and thriving around the Australian coastal cities.

The drought back in the mid to late 2000's put a big dent in the inland yacht clubs

but some of them are recovering. The ISAF world championships are currently being held in Perth Western Australia. The link is provided here.
http://www.perth2011.com/Most youth sailors who sail Mozzies sail with dad's, mum's or friends then either move into their own Mozzie when they are big enough or into other classes.
Regards,
Peter