I don't think forking the current concept would work. The Digg/Reddit model seems to have had its best time. Some new concept should be created. Twitter seems like the right direction to me because you can follow only the people that you think are interesting.
FriendFeed seems to be actively building on that model, with their commenting features. What worries me is that this inhibits meeting new people far away from you in the social graph: I'd like to hear PG's or Paul Buchheit's opinions, even though I don't know them in real life.
