The reality is that growth, in the long-run, is now in Asia (think of the hundreds of millions of Chinese still living in the countryside...).
This round of modernization (the third wave, after England, America+Western Europe) involves 4BN people led by India and China and they're just getting started. Take a pause and think of what that means. Four billion. BILLION.
We're entering the age of Asia. Just wait and see.
I think the bigger fear in China (at least amongst the leadership) is some crazy environmental disaster. Think of the hundreds of millions that live on the Yangtze... a massive flooding event that wipes up power/clean water is much more likely cause of revolution than an economic meltdown.
The US can barely handle Katrina... China is 10x more dense. Something like that would be death knell for CCP control.