I agree with all of the above. If there would be another park built after Shanghai, I really don't know where it would be. Australia's population is quite small; even though I'm sure a Disneyland-style park would be wildly popular there, I don't know if there would be enough guests through the turnstiles to make it profitable enough. In terms of population, the correct move would be somewhere in the Middle East (I know, I know, stay with me though). Since the United Arab Emirates has seemingly fumbled the ball with the Dubailand project, they are moving to a completely tourist-based economy, and the U.A.E. is fairly Western-friendly and [somewhat more] progressive than its neighbors, that would be a good spot to put another Disney park.
Australia's population is only a little more than half of the population of the Tokyo-Yokohama metropolitan area, 22 Mio. compared to more than 35 Mio. In Germany alone we have about 80 Mio. people. And although it is quite a popular tourist destination, not many Americans or Europeans go there because it is a LONG flight and it is expensive. Tourists from Asia however are not enough to bring the masses for a Disney Park, especially not with the two major visitor groups, China and Japan, having their own parks which are even far superior (especially TDL and TDS) ,to anything Disney could build in Australia on a much smaller financial basis. No I am quite sure there will be no Disney Park in Australia ever, or at least in the next 30 years.
U.A.E would make more sense financially, however there is a difference between DL/WDW weather and the UAE. It would be a hard time walking around a Disney park there in temperatures in the 110 degrees and more, during summer season. And there is no guarantee that the present regime will always be there, especially after the number of revolutions in the Arabian world, there is even the threat of islamistic revolutions in the future and ALL money invested would be lost.
It's not easy to place another Disney park with Shanghai being greenlighted. A second park in China made sense but it is difficult to find another location worldwide that could be a success.
All of Africa is far too poor and far too unstable, even South Africa, were a future civil war is still a possibility and the crime rate is insane. Same with South America, more stable but too poor, I already said why even a Brazilian park would be a huge risk (although it would keep us the Brazilian tour groups away, definitely a big plus!) Europe has Disneyland Paris and a second park would be too near to the already existing one as Europe is quite small. Russia would be far too cold and still far too poor, although there is a growing middle class and you need the middle class to make a Disney park a success, you cannot run it with upper class and millionaires. In Asia only India could be a possibility in a distant future however.
Actually I don't think there is the potential for another Disneyland style park anywhere in the entire world, not even in the US with tow parks existing. If Disney would build some different kind of theme park (like Disneys America) however that would be a complete new story.