This is similar to an idea I was toying with a while back but never got around to nailing down. Upvoting or downvoting an item should result in a change on the personal account, but rather than it changing the account's "score" up or down, the system records the vote based on the "type" of item. If a series of items are categorized as "Gossip" and I vote them down, the system learns that I don't like "Gossip" items. An item could be in multiple categories ("Gossip" and "IT") and my past voting would determine whether or not I would see the item on the page (super-roughly "the item was categorized 50/50 Gossip/IT, dpk's Gossip score is -11 and IT score is 10, result is -1, don't show"). In effect, users would themselves be group-able by their votes, so if someone in your "group" posted an item, it would get an automatic bonus. If someone in your "anti-group" (someone nearly diametrically opposed to you) posted something it would get a negative bonus.
Categorization would need to be put to the community, and would be done while the item is on what is currently termed the "new" page. Once the item is categorized the various display scores (as loosely described above) will be computed and the result could be shown to the users.
One side-effect of this is that it allows users to "shun" spammers in to their own "group". They could spam all they want but nobody would see it unless they were really excited about seeing spam.
The idea has (at least) one major serious problem: It encourages group-isolation. This could be partially resolved by always showing a "best of group" block of links somewhere on the home page, which could encourage users to branch out a bit.
As I said, this idea is not fully fleshed out, hence the overuse of quotes and its nebulous, hand-wavy nature. It's a less punitive, more categorical system. It may not scale at all.