Recalling your memory of the story in March 2010 - Google.cn redirects traffic to Google Hong Kong - it ends up that it doesn't make a huge impact to my friends in/from China, 'cos they always visit google.com instead of google.cn.
Now, as Google China needs to submit the ICP license renewal application, they announced a stop in URL redirection from Google China to Google Hong Kong. Otherwise, they application won't be approved. That means, people going to google.cn will no longer be redirected to Google Hong Kong.
For details, please read their official update in the Google Blog - Official Google Blog: An update on China.
Business decision? political decision? Whatever your views on it.