Thanks for all the helpful replies. I've been doing some additional research, and found this article about particularly China:
ATC in China Will Speak English-Only Starting in 1998
Chinese pilots and ground controllers will speak to each other only in English from 1998, Xinhua news agency reported. The "English Project" aims to bring flight communications into line with international practices, the China's Civil Aviation Administration announced.
Forty-seven foreign carriers now fly to China, Chinese civil aviation is booming and increasingly international, and fewer than half of China's 2,500 air traffic controllers can speak or understand English fluently. Some pilots also do not have a good command of the language. Progress in English studies will influence promotion prospects.
http://www.avweb.com/newswire/news9624.html
Obviously, this hasn't taken place, as I flew to China last year, on UAL, and they have a feature where you can listen to the ATC on the audio system, and the Chinese pilots still spoke Mandarin. So, was the above "Project English" aborted? Is anyone familiar with the ATC in China?