At the moment, there doesn't appear to be a full China index based product, but...
Business Week article on foreign ETFs lists FXI (China 25 Index) and PGJ (Chinese companies listed in the US).
Also, you should read
Friday's NYT article on the manic Chinese market.
GXC (S&P SPDR China) started trading in March.
CHNX (similar to PGJ) is also slated to start trading at the end of June, so keep an eye out for that.
More interesting reading at
ETFTrends China page.