National Geographic Television just released a superb program with Aidan Hartley that documents the killing of elephants in Africa for their ivory. The problem is fueled by China's demand for ivory. The program concludes the only realistic solution is that the government of China must say no to the importation of ivory.
The program will certainly be run again on PBS. You can also see a preview and brief discussion of the problem by clicking "Battle for the Elephants."
Writing for the New York Times, Dan Levin did a lengthy piece on 1 March 2013 titled "From Elephants' Mouths, an Illicit Trail to China." It also details the role of China and Chinese nationals in the ivory trade.