One user, http://pekingduck.blogspot.com , has been posting successfully, but cannot actually see his posts go through. I also hear that there are some other weblog sites that may be blocked, but it appears that LiveJournal is still unblocked for the moment.
One solution that I am floating around right now is to set up these Chinese weblogs with full RSS feeds, and have volunteers go to the effort of listing these feeds on RSS aggregators (such as LiveJournal), thereby creating unblocked archives of these weblogs elsewhere on the Internet.
It seems inevitable to me that sooner or later, LiveJournal will be blocked by the Chinese government. However, there are several LJ server sites out there, and lots of other sites which can archive/display RSS feeds. It's always nice to see people come up with uses for technology that weren't originally intended by its creators -- it would be quite a coup indeed if RSS found itself a useful tool to route around Internet censorship.
It is also possible to avoid censorship of weblogs by using proxies. While proxies don't spread the word about censorship, they do quietly give you access to the information you need if you find yourself blocked from the sites that matter to you on the 'net. Information is power...