Add a "Login" button to the comment thread
It's confusing to have an account for the comments on a site and be faced with only a "Create Account" button. For a couple seconds, I looked around for a "Log In" button because I couldn't find one. The "Create Account" dialog does have the option for switching to logging in, but the option should be more on the forefront. As a user, I think I would be more likely to log in and comment if the button was obviously visible.