That date is set as the day ISP's will be required to store every piece of metadata you generate.
There's a "we (ISP's) aren't ready yet" provision that allows ISP's up to 18 months to implement this system if they can't afford it.
So if you would prefer to avail yourself of what is a human right according to the United Nations
http://www.un.org/en/documents/udhr/ (Article 12)
you should first write a letter to you local MP expressing how wonderful it is to now have an additional cost on top of your existing internet service so that you can be assured you will not be spied upon when you merely want to communicate - and avail yourself of a VPN service (based outside of Australia of course).