I'd like to see a system closer to a movie/music suggestion system. Personalize the crap out of everything, show me the stuff I'll probably love, and don't even bother showing me trash I'll obviously hate. And for God's sake, make it trivially easy to permanently killfile other users.
Yes, this is computationally more involved. But the result would be something that would make everyone happier (except perhaps inveterate trolls).