Are you leaving WordPress.com? Would you like to redirect yourblogname.wordpress.com (as well as all of your permalinks) to your new domain name? Have you recently changed your blog address and need to redirect traffic to the new name? The Site Redirect upgrade lets you do just that. http://en.support.wordpress.com/site-redirect/
You must be logged in as Admin under the same username account that registered the blog to purchase an upgrade for the blog.