In a post below, I enquired about all-GPL distros, and I was pointed to Ututo by Chris from Shade-of-Blue. Their homepage features a user forum, where I posted this query. Of course, BIND uses the BSD license so its extremely unlikely that there will be a distro with just GPL. But still, I'm going to see if I can rope an interested student into starting work on a distro that is 'as GPL'ed as possible' (GNU's distro page obviously thinks that its distro is 'free enough' to list). I don't expect anyone to do it single-handedly and so, obviously, will issue a call for help. Stay tuned.