First you need to know what is google panda? Google panda is one kind of algorithm for showing more relevant search result. And as per updation in google panda , it consider the quality first. So it helps to search engine in providing best results. So due to google panda , people use seo start to provide more quality content for better result.
Panda is great for all those who have always wrtitten unique content for their websites, not so good for anyone who hasn't. Although you probably already knew that seeing as your signature says you are an seo expert / guru!