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…
Interoperability with foreign businesses becomes a minor issue. Small business-to-small-business gets a little bit of friction (eg, cannot read your spreadsheet). Some classes of (especially outsourcing) Chinese companies cannot compete. They cannot provide ppc or seo services. Chinese web designers cannot add some Google maps app to a site they are developing for a Canadian client. A Chinese can't reach something on Google code. Annoyances, friction, slight inefficiencies. Being a little annoying (can you use a Zoho spreadsheet instead of Google please) repeatedly can you you client if you are an outsourcing company.
Also, Google provides a lot of non critical, but useful stuff. In many cases, Google is best and the competition can be either close or far. Adwords, Analytics, Docs, Search, Mail. Google does a lot of stuff. In some cases, I would be measurably less productive if I had to use some other product.
They can't just cut off Google with no impact.