I'm not convinced. Google is talking about shutting down google.cn, not blocking google.com from the Chinese internet. I've used google services from China without any issues. Also, the local market in China is much more Windows-focused than in the U.S. I think Microsoft leaving the Chinese market would have a huge effect.
Overall, the question is not whether it has an impact on Chinese business but whether it would have enough of an impact to influence the decision makers in the government.
I'm all for taking the high ground, but I highly doubt this will change the Chinese government's behavior. Google doesn't have such a huge market share in China and leaving will only help local competition (e.g. Baidu) that can be more easily controlled by the government. What leverage does Google have? This is really the classic engagement vs. isolation debate.
The only thing that might have any leverage would be to close all their development offices in China. Maybe they are doing this as well?
Overall, the question is not whether it has an impact on Chinese business but whether it would have enough of an impact to influence the decision makers in the government.