It is called the Google Treads. But remember if your site has a very little traffic, can't give an exact answer but even if you have like 1000 unique visitors, still your site most probably won't be listed in it. But if you used to have a lot of traffic and want to find out if the recent Google changes have made any negative or a positive affect on your rankings then it is one place you can look.
However the previous farmer update according to experts only affected the pages on a given site, not the entire domain. For instance, let's say that you had a site with 500 articles and according to Google 300 of those articles are "bad". Then they would have suffered through the farmer's update. But with the Panda update coming into the action, not only the "low quality" articles or the pages but as a penalty the entire domain can be taken down!.
*. As a fix, according to Michael Wyszomierski, you can remove those pages and move them to a different domain which would help to reduce the "effect". Anyhow, although I'm not judging Google, but they are protecting their interests, so as a webmaster if you want traffic but still don't want to obey everything that Google says, then it is time to get more creative!.