A part of my 5-step solution, one of the parts is voting. I found Newsvine (through business|bytes|genes|molecules) has voting for the submitted stories to push them UP the list of stories (they also have voting on the comments too). Cool. The problem of relevancy still remains, this only resolves the identification of better/worse content.
the main problem I've seen with the new Digg comment system is that it's too easy to vote down legitimate comments. The threshold for a hidden comment is too low. You and a couple of buddies could easily vote down a comment that either does not align with your opinion or is written by a person you don't like.
This next comment is VERY interesting:
Additionally, the whole mindset of digg users towards the new comment system seems to be screwing it up. Users probably feel an obligation to either digg or bury a comment. Therefore, if a comment isn't perfect, it will get buried which harms other users who might find the comment useful. Comments should only be dugg if they are outstanding and should only be buried if they are flames, spam, etc. Otherwise, comments should be left alone at the zero mark.
Perhaps that's a good argument for not having voting down, only having voting up? Several other people comment on comment voting.