I was working on some SEO settings for my website and just found a potential issue with WPMU Dev's listing of Google+ Plugin's page in search engines.
Search "wpmu dev google+": tinyurl.com/levmhmh
The title for the plugin's page on WPMU Dev domain is "WordPress The Google+ Plugin Plugin - WPMU DEV". I don't know but "Plugin Plugin" sounds pretty funky and it's probably due to the fact that you had some algorithm to add plugin after every plugin page.
Anyways, maybe you should setup some custom rule to not add plugin to this page alone, because it just sounds weird.