I work with the Chinese extensively in my job and have traveled there a few times in the past two years. There is no tennis infrastructure there yet. Hard to find courts, private programs, it's not within schools, etc. While the success of Li Na and others will help, it will be the government that will be the make or break for tennis in China. If they see an opportunity for notoriety in the sport and choose to pour resources into it, look out. Otherwise, it will be a long, slow slog for private enterprise to build the sport in the country. That's just how it works there.
Also, big cities in China are so awfully polluted, people do not enjoy being outdoors, much less playing a sport out doors.
"More Sureshs, less Maxima for a better TT." - Power Player