And a note of sanity...
What do we want El Reg to be, a news journal or a discussion board?
At present, most content is written by journalists and expert contributors, and I would like it to stay that way.
If nested comments were allowed, the Reg editorial staff could find themselves spending too much time moderating flame wars, rather than researching and writing real news.
Flame wars are hardly ever interesting to anybody apart from the protagonists; real news is bound to get much more interest.
Decades ago, broadsheet newspapers had to address this issue in their letters columns. Eventually the editor would add the comment "This discussion is closed" after the last published letter.
Discussion boards are ten a penny; real news journals are relatively rare.