Pamela Jones at Groklaw echoes my sentiments over google.cn Indeed, she goes further, and smells Microsoft PR at the bottom of it.
Not impossible, but there's a substantial Google-sceptic movement which is not pro-Microsoft - people like Andrew Orlowski at The Register. Google's size and rapid growth are sufficient to attract considerable scrutiny.
There is a line of argument that accepts Google's claim that they are providing net benefit to the Chinese, but holds that by compromising with the Chinese government's authoritarian demands, Google is nevertheless "dirtying" itself - making itself complicit in oppression.
This claim should not be ignored. I have made similar-sounding arguments myself when I have argued that it is usually better to allow atrocities to take place abroad than to commit them, especially if it is in some area you would not otherwise be in contact with. I base that claim on the effect of ignorance: If you drop bombs on people you can be pretty sure they are going to die, but if you stay out it is harder to predict what will happen to them. The better you understand the politics of the problem, the more confidence you can have that humanitarian violence will actually achieve its ends.
The parallel argument in this case would be that if Google participates in China, the Chinese are definitely going to get censored, but if they stay out, the human rights problems might get resolved more satisfactorily. The relative implausibility of that argument, is, I think, down to the difference between denying people certain search results and dropping high explosive on them.
In this case, I think the effect on China of becoming "complicit" in the world economy and the world media is greater than any effect on Google of involving itself with China.
There is a line which can be crossed, however. Providing intelligence on users to the Chinese Government (as it is attempting to avoid doing with the US government) would be worrying. But even there it is not clear-cut. Business everywhere is expected to co-operate with authorities in detecting crimes, even crimes that would be legal in the company's country of origin. For example, a British company in America might face demands to provide details of users of gambling services.
There is a pretence that there are distinct "human rights" that are self-evident and should be respected around the world, but in fact that is just not the case. The fact is that there are some values that are shared by by many of the world's most powerful societies, and which we believe would bring universal benefit if they were shared more widely still.