Threads on.. particular.. topics tend to generate back-and-forth flamewars that I think this endorsement system may be effective at battling (if the endorsement thresholds are set high enough).
A lot of discussions I've seen that seem superficially to be back-and-forth flamewars actually are instances of intense but substantive debate, and I'd really hate to see even rough-edged but worthwhile discourse suppressed just because someone who gave it only a cursory glance felt put off by its style.
What I'm really tired of is that off-topic, nitpicking discussion threads are often on top. I have to wade through a lot of comments to find the good ones. And I say that as someone who has myself fallen to the "someone is wrong on the internet" syndrome.
What I would like would be to have a tagging system on comment threads, so that I could filter out comment threads with rough edges if I didn't like them, or threads with endless back and forth nitpicking, or threads that have been covered endlessly before. Something like the old slashdot "Informative" or "Funny" system. Then the ones that wanted could troll and flame away to their hearts content, without disrupting the general discussion of a topic. The "no censorship" crows could turn off filtering alltogether and get HN exactly as it is today.
People have different standards of what levels of detail are worth debating about, and on more than one occasion, I've found myself going down what I thought was a rathole with someone who insisted on arguing trivial details, only to realize that those trivial details were key elements of a chain of reasoning that led to an important point which hadn't occurred to me, and which substantively changed the direction of the conversation.
I think a tagging system is a fantastic idea, especially if users can assign different weights to different tags for sorting and filtering purposes. I haven't seen a discussion system, apart from Slashdot's very limited implementation, that allows comment tagging, and a broader implementation might be wildly successful. You could have a voting mechanic that assigns a score to the comment, then allow users to assign different coefficient values to each qualitative modifier to build their own view. No need to limit it to a small set of predefined tags, either; users could define their own tags a la Delicious.
