We see a lot more Aussies coming into our site since so many cruise lines are moving ships there right now.
The difference between styles of cruise lines is vast - I mostly cruise to see the world, and less for the shipboard experience. Therefore I like smaller ships with port-intensive itineraries.
Of course I already live in a hot climate so I do not need to take a cruise to escape the cold like so many regular cruisers do...
But I think you will find that cruising in Oz will tend to focus on "the ship as the destination" cruises with very big and active ships where the ports of call are secondary to the fun you have on board. This is because OZ is so vast that the distance between ports of call is much more than the average Caribbean cruise.
I personally do not see OZ creating as many "rabid" cruisers as the US and Europe have generated - because of so many more days at sea. Cruising is great, but cruising to the same destinations, or spending too many days at sea, gets a little old for many people.
On the other hand, having a wide variety of cruise destinations tends to make cruises more attractive as a vacation option. I don't see OZ as being able to offer that many different cruise destinations.
So - I would try cruising if I were you, but I would not worry about never taking "normal" vacations again.