To a western MMO developer, China's market is alluring in much the same way that winning the lottery is alluring to everyone else. There's a huge market right there, even disregarding the almost stereotypical amount of gold farming associated with the country, but thus far western games have yet to make much of a dent. The only one that's been largely successful is World of Warcraft, and even that has a bit of a tortured history. Scott Jennings has taken the opportunity to expound a bit on what makes China so appealing as an MMO market and why it's been so difficult to get a solid footing in.
One of the points he makes is that, by and large, China hasn't attracted a good portion of the western market either -- Perfect World International comes the closest to making a splash, and it's nowhere near the popularity of, say, Runes of Magic. He also discusses several of the difficulties in negotiations between western businesses and the Chinese counterparts, as well as the government's vested interest in ensuring the market stays solidly in China. The full article also offers as comprehensive a breakdown of the entire World of Warcraft controversy as you're likely to find in one place, making it an excellent reference point for anyone interested in the vagaries of the worldwide market.