Thornbird, the existing regulations plus CASA enforcement, a few accidents in experimental and RAA aircraft, coupled with an increase in security requirements beyond the ASIC, coupled with privatisation of regional airports and perhaps some more medical requirements (sleep apnoea + Colour vision issues) will kill all forms of domestic aviation apart from major RPT, stone dead.
One can already see that if the RAA and SAAA accept the mantle of becoming "designated authorities" or whatever its called, CASA will just pile requirement after requirement onto them until they sink like the commercial GA sector.