Maintaining Hacker News Culture
I feel that HN is loosing that focus because a lot of people are using it as a replacement for Google Reader. For example, today, Amazon acquired Kiva. On the Internet, there are a lot of sources that will post this news. It'll flow from top of the line news blogs (TC and GigaOm) to people who simply reblog stuff to gain traction on their blogs.
On HN, within a span of a few minutes, two people posted the same topic, one a report from ZDNet and the other from TC (see http://news.ycombinator.com/item?id=3726164 and http://news.ycombinator.com/item?id=3726172)
This is counterproductive. Both posters got a good number of points for posting those items, but HN is not a numbers game. Your value is from your comments and not how many items your copy paste from the Internet.
To that end, I propose that HN should implement a technique similar to StackOverflow where as you type in your topic or attach the link, the system searches for similar items and hints at those to alert the poster that they're just wasting their time. If they still insist on posting, HN stalwarts who have negative voting rights should exercise them.
Now here's the irony - Someone would probably already have proposed this exact method on HN, but since there's no easy search or StackOverflow style hinting, I have no way of knowing about it...
(n.b. A lot of people will say that that tech will need a major overhaul for HN, which in it's simple form cannot support such searches and we don't want to upgrade. Why not? Some extra functionality never hurt anyone :) )