[codeslinger]

You might be interested to know that this method has been employed by Cloudmark for many years in their collaborative spam filtering network: http://portal.acm.org/citation.cfm?id=1105677

However, it works so well for them because the consensus on what is "ham" and what is "spam" is nearly universal enough that it can be relied upon to be agreed with by the majority of agents (people) the vast majority of the time. For news links, this will unlikely be the case unless you are actively attempting to create a news site where only a very few have power over what is shown and what is not.

Also, the Cloudmark technique chooses very few people to reward and this is on purpose. They are sparing with the reputation points and quick to downgrade on controversy in order to prevent a high-reputation individual gaming the system. Your news reputation system would likely have to incorporate a similar technique in order to be similarly robust. However, in doing so, I would imagine that most people would not see their reputation ever rise and would likely stop using the system. (due to lack of the "incentives" of which you speak) Cloudmark gets around this because people are already marking emails as spam or not in their email clients already, so there's no marginal cost associated with training Cloudmark's network or building their own reputation.

Its an interesting direction you propose, but I believe you'd be exposing your user base to scale-free network effects in which only a small few would gain sufficient reputation to "move the needle" and the rest would wallow in relative obscurity. This would then essentially replicate the Slashdot of 2000 AD but with the marketing message saying that it was "fairer" because of all the "incentives" people have.

You might want to think of how to structure a social news site as a kind of online auction, choosing a structure in which truth-telling is a dominant strategy, instead, such as http://en.wikipedia.org/wiki/Vickrey%E2%80%93Clarke%E2%80%93...