Split test your wordpress theme, and track test using Google Analytics user defined values.
This plugin enables you to easily add Google Content Experiments control code and/or event tracking into your WordPress pages and posts.
Easily perform A/B testing from within WordPress itself.
Headline Split Tester allows you to have two competing headlines for blog posts. They are randomly shown until one headline wins.
press9-ab-testing lets you create A/B tests from press9's test designer and run the test within WordPress.