WordPress.com has announced new widgets for hosted blogs. The new widgets can be used immediately and added to one of your sidebars under Appearance → Widgets.
The new widgets are:
Blogs I Follow, allows you to display a list of the blogs that you are following via the WordPress.com Reader
Posts I Like, displays an image grid or a linked list of posts that you have liked recently
My Community, widget allows you to highlight all of the activity happening on your blog.
Gravatar Profile, widget that will automatically pull in your Gravatar profile information including your photo, bio, verified services, and custom links.
More info: http://en.blog.wordpress.com/2012/07/17/more-widgets-for-your-blog/