this is yet another proof that China has never been as big as a player as most people around here think it is. [...]
i like that china isn't that big on bitcoin market, they control already the mining ambient, if they were big on the market too, would be too much centralized and risky to have just one country dictating the value,
For Bitcoin nodes & development, the US still "rulez". See
here the distribution of Bitcoin nodes. Although the node density (nodes per inhabitant) is higher in European countries like Germany, the Netherlands and France. (China is actually at position 6).
Nodes do not only mean "more users", but also more Bitcoin businesses - from exchanges to ATMs, payment processors and "real goods" merchants. Trade volume is a bit more centralized because Bitcoin is still too small to have a high-liquidity exchange in every country, but the large exchanges are also pretty well distributed (from the US to Slovenia, Japan, China). The only really centralized Bitcoin business is actually mining with the largest pool sitting in China, but that can change.
In fact, Bitcoin is already pretty decentralized. The "Third World" (Asia, South America and above all Africa) is still underrepresented, but there are upcoming Bitcoin hotspots in countries like Nigeria.