August 3, 2009 — The Top Rating widget works in tandem with the PollDaddy ratings system baked into your WordPress.com account – displaying your highest rated posts, comments, and/or pages in the sidebar of your blog. If you’d like to read more about the Top Ratings widget, check out the WordPress.com support page
July 17, 2009 — The recent addition of the PollDaddy Ratings widget to WordPress.com blogs allows you to add star and thumbs-up, thumbs-down ratings to your blog posts, pages and comments. This video walks you through the basics. For more information check out this support page. A WordPress.org plugin version is in the works.