People say this about every new tld that comes out. It is different to what came before and somehow special until it becomes obvious that it isn't, then people move on.
This is a poo extension, it is better than .com.au is the same way that .cm is better than .com.
The names would have to be worth a significant amount in .com.au to be worth much in .au.
For new tlds the first couple of years is typically the best as people initially scramble, I would factor in a sales declines if people are running the maths.
That is where it is at, seek the safety of .Com. .Com.Au will drop lower and .AU will be a basket case extension.
auDA is already comparing the new extension to .US, .UK and .NZ, yes it will be just as successful at those.