I have read that Google has slowly rolled out the panda 4.2 updates, which impact website rankings who has low quality and spammy content. You can get more information on moose blog about a google algorithm update and in very useful search engine land website. These sites will give you detailed information with examples.
You can read SearchEngineLand, SERoundTable, ... umm, there are others, but those are my favorites for the latest news. What, specifically, do you want to be briefed about? There have been soooo many incarnations of the Panda algorithm up until this point. What makes this one different is that it's a suuuuuper slow rollout (many, many months to complete), which is unique. A lot of Panda-affected still aren't even sure if they've been able to get out of it or not yet.
Like Dani said you can check out with Search engine land About Google Panda 4.2 update like as i did- Check out the following topic in Search Engine Land website - "Google Panda 4.2 FAQs: We Interviewed Google On The Latest Panda Update"
I 'm sure you will get an idea.