The young'uns are interested as evidenced by new groups like "Circulus", who play a blend of 70's psychadelia - medieval dance tunes and a dash of electronica. (They're a bit like Gryphon but not so dedicatedly medieval). I saw them in High Wycombe on Friday and the majority of audience was teen-early 20's. Cool.
I know i'm too old to be considered young, but actually finding out about local folk events isn't as easy for the outsider as one might imagine. If you imagine yourself as a young would-be-folkie, you have no transport, you're not particularly wealthy (understatement), and you probably don't visit the mudcat.
It would be nice if school music emphasised folk a little more, and indeed if music lessons extended as long as compulsory games/pe, but I guess that's not going to happen.
So all I can say is be very very welcoming (first name terms etc.) to those young'uns that make it into your clubs and hopefully they'll tell their friends, after all, young people often have huge social networks.