This infographic shows how many of the Top 100 UK Sites have lost search positions since the Google Panda Update, which many search marketers believe may harm sites that have duplicate content.
This data was visualized for Search Engine Watch (SEW) by Neil Tweddle from Typo-Graphic. You can download the full data visualization here: SEW PANDA UK.pdf
Price comparison sites are definitely getting hit hard. Basically any site with thin content are getting hit. Most price comparison sites have thousands of page will no or little content.
Duplicate content sites will hopefully start getting shut down.