if google still wants to do business in china, they wouldn't choose such an open and high profile stance.
besides they already told the US government of their decisions and soon got back up from whitehouse, clinton and locke. and then clinton talked about anti-filtering tech.

all signs show google's action is well pre-meditated. hasslings from baidu and china government seem nonstop all those years. gmail hacking is just the last straw to the "enough is enough" breakup