we have an seo plugin that we have written to increase your long tail traffic in wordpress.
You can DOWNLOAD IT FREE HERE: Wordpress SEO Plugin
Its already quite popular with around 4,000 websites using it - it has also had quite a lot of coverage on popular seo sites:
you can read all about it here on seoMoz:
Other places where it has been featured:
Search Engine Journal
SEO Black Hat World Forum
Irish Webmasters Forum
BlackHat World Autoblogging
So try it now!