This, combined with a burying system to get rid of junk stories, could clean up the 'new' section substantially. It would also be useful to factor snr into the computation; the nature of the karma system, which makes it more advantageous (at a marginal level) to submit a story than a comment, encourages a shot-gun approach to submission; SNR would combat that.

EDIT: Ha, points to jwecker for posting about SNR while I was writing about it.