In my random googling (because I don't have to go to work for another hour yet...) I've found a link that may answer a lot of people's questions:
http://gls.arrivealive.vic.gov.au/component/option,com_fastfacts/Itemid,140/You fill in your own circumstances and it explains how the new rules affect you personally.
"Thanks for your 'Fast Facts' inquiry. As you are 18 - 21 years old and you obtained your probationary licence after 1 July 2007 but before 1 July 2008, then the following rules apply to you:
* You must stay on your probationary licence for at least three years.
* If you were tested in a car with automatic transmission, then you can only drive this type of car.
* You must comply with restrictions on driving high powered vehicles. Click here for the restrictions that apply to you.
* You must have a zero blood alcohol concentration (BAC) whenever you drive
* If you are convicted of a drink driving offence involving a BAC of .07 or higher, you must have an alcohol interlock fitted to your car for a minimum of six months when you return to driving.
* You must display your red P plates on the front and back of any car you drive.
* From 1 July 2008, you must display a green P plate, not a red one.
* You must carry your probationary licence with you whenever you drive.
* If you incur five or more demerit points in 12 months, or 12 or more in three years, your probationary licence may be suspended.
After at least three years on your probationary licence, you will be eligible to obtain a full driver licence."