I recently moved my website to wordpress.com, and found replacements in its settings for almost all the plugins I was using on my self-hosted WordPress installation, with one important exception:
http://wordpress.org/extend/plugins/broken-link-checker/
I found this plugin extremely helpful for emailing me when links went bad and correcting them everywhere they appeared throughout my blog from one settings page. A search on "broken links" in this forum didn't find any discussions on this topic. Has wp.com considered incorporating this plugin in its sitewide offerings? I think it would be an invaluable tool for all wp.com authors.
Thanks for your time and consideration,
Jeff Covey