I love the idea of stopping the 'split discussion' issue, but I feel like it's at odds with a site like HN where stories fall off of the front page so quickly. I'm not able to read it all day long, and I rarely look at it in the evenings. Especially when we have articles about potential gaming of the article positions, it seems unrealistic to expect that you would have a chance to actually get the real 'news' at any given point without duplicate posts.
What I mean is, there are certainly more than 30 in-progress topics appealing to HN readers. If I look at the front page in the morning and again in the afternoon, I'm only going to get a small subset of the topics that are out there. That's why I appreciate duplicates so much... it's really the only thing that makes a site like HN relevant to the occasional reader.
Anyway, thanks for supporting me even though I wasn't the most ambassadorial. :)