Downvote if you will, all the same, I find most HN discussions to be of relatively low-value, and also it's not easy to vet whether or not someone's credentials align with what they're writing. I come across interesting links on HN all the time, and I wish I could have something to tell me "Oh, there's a LtU user with hundreds of posts discussing this with links to papers and proofs."
My personal perspective is just that way, I don't see myself coming across anything and thinking "Gee, I wonder what HN thinks about this."
I love the idea though. I wish browsers didn't suck so much. I wish Opera had won more, and maybe we'd have lots of different browsers, infinitely configurable like emacs/vim, with my whole little customized universal browsing tool. Extensions are an adequate compromise, it's just that the kind of person who thinks this stuff up, could so much MORE if browsers weren't so limited.