Google announced earlier this year that they had been working on the Penguin 4.0 search algorithm update. This would change the way search results are ranked, affecting a lot of SEO practices.
Previously we had been expecting the update to be released by the end of 2015. Google had also stated they expected to release it in that time frame. For a lot of webmasters, this was great news as Penguin 3.0 had affected their rankings in a big way.
Now, after being questioned by a number of people, Google has confirmed that the Penguin 4.0 update will not be happening this year. With that being said, considering how much time and work has been put into it, the algorithm update is likely to drop pretty early in 2016.