You already provide lots of Facebook integration, like profile badges, like buttons, etc. I'm not sure if there is a way to use Facebook's "Insights for your webpage," however.

http://www.facebook.com/insights/

I understand that it's not possible to add metatags to the head of a WordPress.com blog. I would just like to request that a feature be added similar to the Google and Bing webmaster tools that allows you to input a content value that Facebook provides at the link above. Here's what they say:

Get Insights for your Website
Add a meta tag to your webpage

Gain access to insights for your website by adding a fb:admins or fb:app_id meta tag to your root webpage, linking it to your personal account or an application.

The metatag looks like this:
<meta property="fb:admins" content="12345678910" />

Thanks for considering my idea!

- Eric