That comment gets an upmod for being a fertile suggestion: even if it doesn't work as-is, it provokes some thought about what behaviour we actually want to reward.

IOW, we are saying: "We hate most spolsky/coding horror/raganwald/..." posts, but from time to time there's a good one in there, so please ferret out the good stuff for us. Posting stuff from Paul Graham or Tech Crunch is not going to be rewarded.

Sounds suspiciously like re are rewarding risk-takers. That seems to be in the spirit of hacker news.

The next most easy option is to delay submissions by an hour or so. If two or more users submit the same URL in one hour then no-one gets credit. This would ensure that two or more bots monitoring the same blog would cancel each other. More generally, it would encourage more diverse content to be submitted.