Hi Footy, Good questions that you have obviously seriously...

Hi Footy,
Good questions that you have obviously seriously thought about unlike some posters oh HC.

Speed/bandwith is a big thing, and bandwidth usage is increasing exponentially, so although only high usage business etc would need anything above 25/5 at the moment it does not mean this will be the case in 10-20 years time. There will be new products and services that have not even been invented yet that will come out in the future that will require more and more bandwith, this has been proven with the switch from 56k dial up to 20,000k adsl the same will be the case for high speed BB, if you try and browse todays website on dial up you will be in for a shock, and forget about youtube and anything like that.

Your FTTN connections looks to be just the best you can possibly get, this is great, you must have very new copper going from your node to your house, in many places around Australia the copper is in disrepair and users will not see the great performance you are getting. Also telstra is currently spending about 1 billion a year in copper maintenance and that is doing the bare minimum they can to keep themselves out of court, so for FTTN we have to commit to huge yearly repair costs and maintenance.
Also as FTTN will hardly be cheaper initially, (a recent report advised it could cost more the FTTH) and will cost a lot more again to replace in the future what is the point??
if you were building a house and had no children but planed to have 3 in the future would you not build the extra bed rooms to start with only to have the extra costs and mess of renovation down the track??

Also all wireless requires a fiber backbone and has physical limitations you can't have mass usage on it. it can't handle large amounts of people and the cost per data transfer on wireless is actually way more expensive then putting in fibre, if wireless could work then it would obviously be a no brainer, we would use it for everything, unfortunately that is simply not possible.