Panda update rolling out
Earlier this week, we started a slow rollout of an improved Panda algorithm, and we expect to have everything done sometime next week.
Based on user (and webmaster!) feedback, we’ve been able to discover a few more signals to help Panda identify low-quality content more precisely. This results in a greater diversity of high-quality small- and medium-sized sites ranking higher, which is nice.
Depending on the locale, around 3-5% of queries are affected.