Picture from his official site.
It's hard to overstate how important Liu Xiang has been to this Olympic Games. In some ways, China has built its entire Olympics around Liu Xiang - and the hope that he would defend the Olympic title he won in Athens. You can barely go more than a few metres in Beijing without seeing a poster of Liu - advertising a selection of ice creams, soft drinks, credit cars, sports shoes, and fast cars. Those adverts may now have to be speedily re-done.
Why was Liu Xiang so important? He was the first Asian man ever to win a gold medal in an Olympic track event (in Athens 2004). "His achievement made us feel that we could achieve anything ourselves as well," said one woman. So, Liu Xiang's expected gold medal in Beijing was about Chinese national confidence - it was about China feeling that it could do anything that any other country could do.
I don't know what kind of effect this will have on the collective psyche of the Chinese athletes. I guess it's a good thing that it happened closer to the end of the Olympics rather than the beginning, but I can only imagine how this must be affecting everyone else, especially the other Chinese athletes who have been inspired by Liu Xiang. As the BBC reporter says, the Olympics in some ways was built around Liu. I'm an American citizen, but I admit being sad over this because as a male of Chinese descent, it was great to see Liu smashing those stereotypes about what Asian people can and can't accomplish, especially in running, which is probably as basic a sport as any.
Some people are bashing him on the BBC site, but hey, injuries happen to the best of us. Oh well.