Antitrust authorities in the U.S. and Europe had already given their OK for the merger. Most of the conditions that Chinese authorities applied to the deal were already voiced by the U.S. and Europe, including an obligation for Google fairly license the Motorola patents it coveted and, which were, Google said, the primary reason for the deal.
However, one key condition came out of China's approval. Google must keep Android free and available to other OEMs beside Motorola for at least five years. This stipulation was likely added as a guarantee for other OEMs, most of which reside in Asia, that Motorola Mobility would not receive preferential treatment as a result of the acquisition.
Technically, of course, Android doesn't "belong" to Google. It was created and developed by the Open Handset Alliance, of which Google is a member (although Steve Jobs disagreed about its creation, calling it a "stolen product").
Still, the reassurance given by this condition of the deal can't help but bolster the confidence of OEMs that might have been fearful about Motorola's role in Android. After all, it's well-known that Nokia has a greater say in Windows Phone than other OEMs.
Although not yet confirmed by Google, it's widely believed that its next Nexus device, generally created by only one OEM, will be "gifted" across several OEMs. In essence, that modified Nexus program will give several other manufacturers the same access that Motorola might have.
Update: On Tuesday, May 22, 2012, Google announced the acquisition was complete.