Facebook for Tags plugin connects those who “like” with future related posts. You need to run WordPress with PHP version 5 or higher. Rikard Kjellberg explains:
Write your WordPress blog posts as you normally would. Define your posting with appropriate tags or assign categories. Once posted, it will have a Facebook Like button linked to it. Any reader who clicks the Facebook Like button will share the article but also receive additional updates anytime you write a post specifying the same tags or categories.
So, any Facebook fans should give this a try so instead of a one time event, you have ongoing updates and sharing from your post tags or categories.
Available at: http://wordpress.org/extend/plugins/like-for-tags/