From the article: "Google today listed changes it made to its algorithm in January.
As previously discussed, the biggest takeaway from that (at least in my opinion) was an increased focus on freshness through not only updates to the “Freshness Update,” but also through changes to universal search, which focus on the queries that deliver news results.
The company also addressed a recent Panda tweak:
High-quality sites algorithm improvements. [launch codenames “PPtl” and “Stitch”, project codename “Panda”] In 2011, we launched the Panda algorithm change, targeted at finding more high-quality sites. We improved how Panda interacts with our indexing and ranking systems, making it more integrated into our pipelines. We also released a minor update to refresh the data for Panda."