The fundamental problem that isn't going to be addressed in this legislation is the age of the Australian fleet; for example, in the UK we ran cars that were no more than 7 years old when we bought them (and the oldest was 10 when it came off the road). Here? 1978 Land Cruiser, 1992 4Runner, 1992 Yam XT600, 2007 Yam WR250 - and in all honesty, those were about the same price as we paid for any of our 7 year old cars.
Whilst this is going to take effect, looking at the age of the vehicle fleet it'll take about 10 - 15 years for it to start to make an impact.
There are a number of other things that need to be addressed, and might avoid this all together:
1) Making it harder for inexperienced drivers to get into large, (relatively) fast cars that are RWD
2) Annual road worthy inspections for all States for vehicles over 5 years old (UK was 3 yrs, but corrosion is often more of a problem)
3) Street furniture and infrastructure needs to be designed to be more friendly in an impact, rather than solid and immovable (requiring the above Falcon/Commodore to bend around it, reducing the space in the cab for the occupants).