Delicious does this pretty well (though the way they do it doesn't completely map to most social news sites) and Reddit has started doing this with its topics feature... Maybe YC News needs to implement something similar? Thoughts?
All I know is even with the risk of missing some good posts, I do not want to see anything from the users that submitted and upmodded this post, and simply moderating this will only sweep the problem under the rug temporarily, and conversely the users that like this post will want to continue making posts like this in the future...