JConverter is a component for Joomla! 1.5 allows you to convert your WordPress blog into a Joomla site. It can import users, blog posts, categories, pages and even links from your WordPress blog to Joomla.

Just install it, select the options you want to imports from WordPress and click on “Start Conversion”. It queries the WordPress database for blog posts, pages, users, links and categories and converts them to Joomla format. All in just one click.

This is BETA release and there are some new features planned in future. As of now, there are certain limitations of JConverter which you can find under configuration panel of component.

More Details and Download:
http://www.sopantech.com/services/free-extensions/cat_view/46-joomla-extensions/50-components.html