For years, webmasters and SEOs have been asking Google for a way to specify which links they do not want Google to count (positive or negative) towards their rankings.
The concept is simple. You go to your link report in Google Webmaster Tools and have an action button that says "don't trust this link" or something like it. Google will then take that as a signal to not use that link as part of their link graph and ranking algorithm.
The reason webmasters and SEOs want it is because they want an easy way to remove any negative links that may be hurting their sites from rankings.
But do SEOs really want it?
What I can't understand is why hasn't Google released it yet? It is a great way for Google to do mass spam reporting by webmasters and SEOs without calling it spam reporting. You will have all these webmasters rush after a penalty to call out which links they feel are hurting them. Google can take that data to back up their algorithms to on links they already know are spam but also find new links that they might not have caught.
That is a win situation for Google. They will find more spam this way than via a basic spam report tool.
It may be perceived as a win for SEOs and webmasters, because they can easily discount links that might be hurting them.
But is it really a win? I have no doubt that most of the links a webmaster decides to discount would not have been marked as spammy by Google already. So who is really benefiting?
You go through links, links that might be positively helping your site and discount them and then hand over the reason why you want to discount them to Google.
I really do not see why Google has not released this functionality yet? Am I missing something? Who cares if it really discounts things, Google would be collecting tons of data.
Forum discussion at Google Webmaster Help.
Update: Matt Cutts of Google said at SMX Advanced to expect this type of tool within a few months.