Cairns has everything needed for a wc round. As a bonus, the track isn't a mole hill either.
Cairns was a wicked venue in 1995 (and of course 1996), it just didn't kick on from the worlds. For a WC round you need money (often from government), private $s and a strong volunteer base (club, locals etc)
The way I see it there needs to be at least two rounds in the region (Asia, Australia, New Zealand) to get the riders and teams here (it is a long way to and from Europe and North America)
Re the size of the Stromlo track it has all been said before, it is not the biggest however the way I look at stromlo is that it is a precision hill. I could draw a similarity to a motor sport, one wrong pedal stroke (or corner) is the difference between top of the podium and not. Racing at Stromlo brought the closest finish on the podium ever, I think that makes for good racing. The top 5 riders last year in the world cup were the same top 5 at the world champs, so the cream of the crop still rose to the top (perhaps the top of Stromlo is not quite as high
).