We haven't had the greatest relations with the Chinese, although they haven't given us half the crap on Iraq that the Russians or French have. We need to be burning up the phone lines to Beijing working to force a diplomatic solution in concert with them.
I'm no expert on foreign affairs, but perhaps PRC's open embrace of resolution 1441 prompted Russia and France to get on board. Traditionally, PRC obstains from such votes, as they did in 1990.