In this article arises the question of the loss of young people involved in the kernel development. Ok the problem has been half broken already in the arguments, as you noticed: in fact these people are there already.
Being one of them, I pay attention to such folks. Even if the age doesn't appear to their email headers, you just figure it out :)
They are here in different ways, knocking for time to time, hesitating or being radically involved, depending on the degree of their shyness and experience. And they are here everywhere: arch/, kernel/, drivers/, mm/, etc...
And there are very promising people among them. In fact the real problem is not "how to attract fresh blood", it's rather "how to keep them" and how the community should behave in this regard.