China will overtake the USA sometime this century....

[averyblund]

The thing with China is that at some point as prosperty grows their population will begin to become more and more aware of the subversive tactics of their government. If China expects to become the dominant superpower they are going to have to change their stance on human rights and free speech. Ever wonder why there are no prolific Chinese writers today? or colleges? Censorship is a disadvantage in a free market, and when the Chinese people see that they are being help back by it they will put pressure on the government or migrate to other nations.

If you ask me India is far more likely to be the next world leader. Their openness and ability to assimilate makes them a threat of epic proportions to China. Similarly Russia has a chance to make a hell of a comeback thanks to their massive natural resources, something China lacks.