We are probably many years away from this happening. China is still a manufacturing nation. They are the factory where other nations that actually research and develop products go to get them produced.
Just because you can enslave millions of your citizens and put them in factories at minimum wage while you collect millions, and have no regard about polluting your own backyard, it doesn't mean that you are now close to being the leader of the free world! Oh wait, they are not even free.
Before China is at a point where they can become leaders, many years will pass if it even happens at all. IMO I actually don't think it will ever happen. They will continue to be a cash rich and powerful country, but will never have the clout that the United States has.