Probably the states as they are now are independent countries, i highly doubt many, if any of the colonies would remain under the UK government for too long (maybe up until WWII or a little past that, because the colonies would be restless of course and 2, can't see the UK being bothered to keep it, sure theirs minerals but its the other side of the world and they're not the french), the only place i could see being under the UK still is maybe the smaller population centre's (Northern Territory, Tasmania, those two on their own would probably struggle more economically). I'd imagine some border skirmishes and even some low end wars may occur as a result of trying to gain land/resources. Possibly some of the colonies merge because of Economic reasons (Victoria and Tasmania).
NSW I'd imagine would be the most powerful of the potential nations, followed by Victoria, Qld (maybe Qld ends up with the entirety of Papua, its possible), W.A. Then S.A. Economically they'd all be very different and over time i'd imagine even culturally and the types of economy they run (even politically) they would be very different.