I agree that dilution of new page isn't a big problem and the crowd aspect should ensure interesting links go up. The problem to solve is split discussions so

I agree that dilution of new page isn't a big problem and the crowd aspect should ensure interesting links go up. The problem to solve is split discussions so I think it would be great if duplicate links would be automatically merged and the discussion page unified. The more challenging problem to solve is how discussions about stories that are almost identical or link to identical stories could be merged. Could there be an option to view discussions independently or show a page that auto-merges similar discussions?