I found this study on "Internet Filtering in China in 2004-2005: A Country Study" http://www.opennetinitiative.net/studies/china/
Seems like there blocking lot of political and news related contents as well, which is very annoying. Back home (Sri Lanka) we had a period around 1989 where the news contained only the praises for the government. No criticism was allowed. However, according to the history these things could not last long. It is up to the Chinese people to decide to accept this or not in their coming elections. (Hope it is not blocked )
IMHO, blocking peoples' freedom to express ideas and criticizing something is really *bad* but with respect to other blockings I feel that it might be the way they have found to keep that country from crashing into pieces with 1.3 Billion people.