I've always assumed that Kopyleft basically means "public domain". Although looking it up on wikipedia, it seems that legally, it doesn't mean anything, and therefore default copyright law would apply.
Anyway, assuming it means public domain, I agree with some of the posters that it's a bad idea to consider it dogma.
On the other hand, the more discordian material is free to use, the better, IMO.
Personally, if I were to pick a license for my discordian works, i'd rather go for the Creative Commons Non-Commercial / Share Alike / Attribution license.
Mostly for the reason that if I were to publish something public domain, and someone uses it and makes a lot of money out of it, I'd feel kind of sour about that. But if someone sees my work, thinks of something to make a lot of money out of it, the CC license doesn't prevent them from contacting me, so we can work out a specific non-transferrable commercial license (not even necessarily for a fee).