The
discussion on PhysicsForums concerning the kids solution is pretty interesting. The consensus seems to be that the media is jumping the gun a tad. They seem to think the kid was able solve the DE using a Taylor series, which doesn't count as a "closed-form solution". Although, still impressive for a 16-year-old.
As HallsofIvy said on the forums, "What really seems strange to me is that the solution to a problem proposed by Newton and unsolved by mathematicians and physicists for 300 years would win
second prize in a local school competition. I want to see the paper that won the
first prize!"