From the Official Google Blog (follow link for the whole post):
So earlier today we stopped censoring our search services—Google Search, Google News, and Google Images—on Google.cn. Users visiting Google.cn are now being redirected to Google.com.hk, where we are offering uncensored search in simplified Chinese, specifically designed for users in mainland China and delivered via our servers in Hong Kong. Users in Hong Kong will continue to receive their existing uncensored, traditional Chinese service, also from Google.com.hk. Due to the increased load on our Hong Kong servers and the complicated nature of these changes, users may see some slowdown in service or find some products temporarily inaccessible as we switch everything over.
I would expect to see China censor Google.cn very quickly (which would prevent the re-direct to Google.hk). It will be interesting to see if China will then take the next step of censoring Google.hk and possibly other Google properties around the world. It would be easy for Google to set up any or all of them to return results in chinese if the browser is detected to be configured in that language.