Is the genre Extreme Folk? Or is the instrument an Extreme Folk Guitar? Either way, I can't quite see it as a puff, a whimsy, a light-hearted effusion taking pleasure in its own deftness because that's how much super slick muso folk comes across leaves days anyway, yet gets much glory, laud & honour out here in the Cultural Tundra of Mudcatland where the ageing hunter gatherers cling doggedly to the old ways whilst the young bloods have settled on more fertile lands with their new fangled ploughs and cruck-frames...

As we've seen over the years this term FOLK is vexing in terms of its definition, or rather its lack of, and the OP (especally) is forever telling us FOLK is not about genre, yet dares imply this might be a Genre Issue. Hmmmm. In terms of the 1954 Definition there seems to be quite a community of cunning guitarists out there evolving all sorts of styles of playing by taking advantage of the electro acoustic dynamic whereby strumming & finger picking becomes pretty much ananthema to their craft. I met a Japanese chap in Forsyth's in MCR a few month back who was using a similar technique and he spoke of quite a scene in Toyko where this sort of thing is pretty much par for the course.

And then there's The Chapman Stick:

http://www.youtube.com/watch?v=dYKB6Lag-wg&feature=related

And don't go telling me that that isn't folk because I've heard it being played in pretty much every folk club I've been to for 36 years.