Digg.com with new commenting system
Actually it's solid enough that Newsvine is already thinking about adopting it, a post that initiated a quite intersting discussion about basically people think commenting-systems (and esp. the one on newsvine.com) should work to keep the comments section free from junk while basically still not opening it up to abuse in the other direction. For now I personally don't see the need to change all that much on the commenting system but it's definitely a good idea to think about the future considering how fast digg.com went from unknown to the 2nd /.
Whatever newsvine will do with their commenting system, it will probably be quite interesting considering their "vote-up-only" policy and how you can keep with that and still offer some useful filtering ;)