There have been some questions about how Australia may remove sales tax from bitcoin and other digital currencies.
DLA Piper have looked at a few scenarios ranging from considering digital currency a foreign currency which is not subject to sales tax or amending legislation to define digital currency as a GST-free supply. The tradeoff between the two seems to relate to the amount of tax credits businesses using digital currencies can claim (more details here).
This publication expects that the best way would be to ask the Tax Office to change its stance as the UK did. Legislative amendments may be too long-winded.