It's always a bit dicey trying to define one genre from another, and even dicier defining musicians who dabble in diferent genres constantly as Neil does, but the folksinger has to be the defined as the travelling minstrel - the "poor player who struts & frets his hour upon the stage and then is heard no more..." Neil is not one of them.
But, many of his songs will be the folk songs of the future. As someone mentioned earlier, some of them already are.