Google just implemented one of the largest changes to it's search ranking system--a change that affects 35% of all websites and search queries.
Google makes more than 500 changes to its algorithm every year. Such changes are often small, and do not affect a large swath of the search market. This change is different. Almost any astute searcher may see SERPs affected by the change in algorithm.
The goal of the recent update was to improve the timeliness of data within Google's massive cache. Originally the search engine was focused on listing websites that were, often times, years old. As social media and online interactions grow faster and faster, the desire for timeliness and speedy, breaking news and status updates is making the search giant a little obsolete. Google is taking action by focusing on including data that includes everything from 10 year old website pages to second-by-second updates--similar to Facebook and Twitter. People often use the Web as a real-time news feed, and Google sees the longterm value in this trend.