I predict this story is going to become another "voyager leaving the solar system" type of thing. By one measure or another this is going happen once or twice a year for the foreseeable future.
We should be observing history at its slow and steady pace. As India and China lead the world within a century, the United States will have to learn to fit into its new role farther down the ladder. We could be the Great Britain of the 22nd century.
China's growth is 'sputtering' because the government is starting to make the sort of reforms that everyone said they needed to make to move growth away from being driven by debt-funded infrastructure spending, but were too scared of making because of the short-term costs. Now that that's happening, the media narrative has shifted to "economic growth targets dropped 0.5%; economy in imminent danger of collapse".