I also voted for merge. Perhaps when a comment formatted in a particular way recommending a merge receives n number of upvotes that could trigger the merge?
It's difficult because so many blogs and other news outlets in the tech media world travel in flocks. After one does some original reporting the rest jump on the story and (usually) cite the original source. However, the original source for the story doesn't always rule on HN in terms of hosting the main conversation. Sometimes this is because of the timing of the submission and sometimes one of the members of the 'flock' are higher profile and gain more knee-jerk upvotes (TechCrunch comes to mind).
It would also be nice to have an "alternate links" section on top of the comments page, with possibily of upvoting the alternate submissions.
Even better if an alternate link could replace the main one if it is voted as more relevant (ex main blog post replacing a post merely quoting it)