It is too early to tell how the Panda Update is going affect your sites rankings, as there are always winners and losers with each update. Since the start of May we have already seen some sites gain in organic traffic and some lose organic traffic.
A good example of a major site that has been impacted negatively is eBay. Here is an excerpt from a blog this morning posted on Moz.com by Dr. Peter J. Meyers about how eBay has lost a significant percentage of the Top 10 Rankings.
In this example, you can see that eBay’s main sub-domain (www.eBay.com) dropped from #6 all the way to #25 in Moz’s “Big 10″ domain rankings. This is a very significant and quick drop, especially for a company of eBay’s size and scope.