Your first step is always to call your telephone or internet service provider to see what they offer in relation to the NBN. After that there are 3 options.

What you get for each
What will it cost
Do a little
Wait till the NBN arrives and then contact your preferred service provider to arrange to have your existing services switched over to fibre broadband.
You will probably have the same or very similar service.
In most cases there will be no up front cost for moving your existing services to the NBN.
Do more
In preparation to switch to the NBN you may want to install some home dedicated networking technologies to devices that require high bandwidth like Smart TVs so you can get higher reliability.
You get your high bandwidth device such as Smart TVs and Media servers connected with dedicated network links providing you high speed connectivity.
Your up front cost could be as little as $100 for Power Line Communication adaptors or a couple of hundred dollars for some cabling.
For more information on home connectivity solutions click hereNote: Any cabling work must be done by a registered cabler
Do a lot
Have Category 6 cabling to every living area of your home from one central location. In Australia this is called "Smart Wiring" but you may also see the phrase "Structured Cabling"
You get high speed connectivity to every living area that supports power over ethernet and optimised location for your wireless access point.
Installing a basic entry level cabling system in a three bedroom house starts from around $1,200 - $2,000.
For more information talk to your registered cabler or refer to Smart Wired®  Note: Any cabling work must be done by a registered cabler
Did your cabler give you the TCA-1 form? It’s the law! More Information