I think there's a huge disconnect between the quality of LWN's content and the quality of the comments. There seem to be some highly opinionated curmudgeonly people here who really have the capability of destroying conversations, and it's a real disappointment to me.
I subscribe to LWN because its articles are valuable to me as a professional programmer, and I think the editors should try to bring the quality level of the comments up to the standards one finds in professional venues.
If it were up to me, I would:
1) Require that everyone who wishes to comment supply their real name. Have the real name attached to every post and police the use of aliases.
2) Provide a publicly viewable comment history for every member, indexable by real name and user name.
3) Allow people to edit or delete posted comments for a period of time. Give people a chance to fix their own enraged-posting mistakes.
4) Draft explicit guidelines for posting, requiring people be on-topic and avoid personal insults.
5) Delete all posts that violate the guidelines.
Of course it's you're site. But I think you overstate the 'slippery slope' or 'anti-censorship' argument. LWN is hardly the only place on the internet that blowhards can make themselves heard.