Would the Party leadership go, I don't see na obvious candidate for an unquestioned successor -- I'd expect various local Party barons, democratic and nationalist forces to vie for power, while the peasant and worker rebellions the Party now routinely puts down could blow up big-time regionally.
The decision to allow entrepenuers (i.e. capitalists) membership in the party several years ago means that now there's a fusion between the rising capitalist class and what remains of the party and military bureacracy. So you have a military-industrial complex in waiting. If south China can hold their shit together, and the rest of the country crumbles into warlordism then you're still going to have migration. Possibly more profound then now, and the migrants will have even fewer rights if they are not citizens of this south China state.
As for resources, I think that if US power is checked as it is now with the Iraq war, then this state could act agressively in the South China Sea, and develop a closely controlled source of oil. Further, Australia is a country where natural resources are being transferred to the Chinese. Australia supplies, coal, wheat, etc. In the long term, if the US can't enforce territorial integrity in Asia, is the Australian position tenable? Or does Australia fall under Chinese regional hegemony?
And with Australia's natural resources, and naval power to open markets, the new Chinese state is a real contender. And I'll give my consent to any government that does not deny a man a living wage-Billy Bragg
They seem to fully understand the state of affairs on this planet. They are picking their friends and their fights; and they seem to have absorbed the idea that it is easier to shut up or to tell the truth than to remember your lies.
Australia is another trading partner, not a target. China understands trade quite well. I think that 2000+ years of an almost consistent nationhood - with plenty of lessons learned - does inform them to a major extent today. They've seen militant imperialism from every side. I think that they see the downside. (On the other hand I might not want to be Vietnamese.)
As far as dumping dollars, my guess is that they are already in the process of adjusting their stake, but it won't go into full dump mode for the reasons stated elsewhere in the comments. For one thing who is going to take a trillion US$ right now? Nobody. My guess is that their recent statements were partially for the fun of tweaking BushCo, who are currently working on the first joints of their fingers, having already gnawed through their fingernails. paul spencer