What evidence is there that HN commenters are actually "thought leaders"? That sounds like just the sort of hubris the 4chan thread makes fun of.
I don't think we should be completely written off as "geeks", you're right about that, but it should certainly be acknowledged that we're a small (heavily) biased sample of the general population and our preferences need to be taken with a grain of salt.
Which in the eyes of most people other than those you have listed, makes us geeks. If we're talking about leadership, it isn't so much how we see ourselves that matters, but how others see us.
It doesn't require a crystal ball to know when a product solves a problem for users in a way that leaves a good taste in one's mouth.
However, I'm still discovering great products and apps from technophiles who have found solutions to problems that impact me. I've also left detritus behind, not because the awesome folks of HN said it was time, but because of well reasoned thoughts that start here (I tend to favor here) and in other technology springboards.
At the end of the day, I believe that mainstream ultimately wakes up. The kernals for change start small though.
Personally, I don't follow a compass held by just the tech pundits or mainstream - I head toward the smell of good user experience.
I have seen very little actual evidence of this, unless we're talking tautological, "all the predictions that came true came true, just ignore the rest", weathervanes. Still waiting on those social-network-based search engines to reign supreme...