Back in 2010, Google pulled its already limited services out of China. Everybody moved to other search engines and Android phones shipped without the Google Play Store, or the Android Market as it was known back in those days. There was, of course, a reason for giving up such a gigantic and lucrative market. That reason was censorship that they felt was draconian and infringed on a moral right of the people to information. As an act of rebellion of sorts, they ignored demands by the government to censor more content and instead directed traffic to their Hong Kong operations, which were not censored. Naturally, it didn't take long for Google's services to get the boot from just about every ISP around. To add insult to injury, Google's servers and the operations of multiple human rights operatives suffered a cyber attack from within China. When the government finally pulled the plug, Google made no move to reverse that. Just like that, Google decided that getting into a market twice the size of the United States' population wasn't worth the trouble.
Despite all that happened, Google is hiring for a good number of positions and gearing up to break back into the Chinese market in a big way. Already, there is talk of building a custom app store compliant with government demands, as well as censoring the Google search engine and figuring out which core Google services can be offered without constituting a violation. A market that big and a product as useful as Google's services are a match that simply cannot be ignored.
American companies may not be used to having to comply with censorship demands as they operate abroad, but it's a consideration that must be taken into account. Google learned this lesson the hard way in China and now apparently feel they have the manpower and resources, as well as the knowledge and experience, to give it a real shot this time. Google plans to comply with all applicable requests in order to stay in business in China. No exact timeline was stated for the rollout, nor whether Google would have to negotiate with the Chinese government beforehand.