When I first heard about it, I thought the same, but there's a number of people who are taking it seriously now - the course has structured assignments with deadlines and a user forum ... check it out: http://www.cppgm.org/index.html

It wasn't taken seriously because it seemed like a joke, due to the sheer size of the problem, at the time :)

Now that they are actually releasing exercices, I think they are on a very good path to realizing their goal.