+Pierre Far works at Google, UK today revealed in his timeline update on Google+ that Panda Update is rolling out today . Below is the extract of the story.
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.
Paragraph Courtesy : Google+
Read how to create high quality post for Google
Bottom Line : If your site have low quality content or lesser amount of content say below 300 words in a post then it will be affected by this update.