Adds required inside labels

comment_form.php

/**
 * Changes the default WordPress comment form fields to match the way I like them, with the required * inside
 * the label.
 *
 * @param   array   $fields     req     The default fields for WordPress comment forms
 * @return  array   The fields the way we want them to look
 *
 * @uses    wp_get_current_user
 * @uses    get_option
 *
 * @since   1.0
 * @author  SFNdesign, Curtis McHale
 *
 */
function wp_theme_t_change_default_comment_fields( $fields ){

    $commenter = wp_get_current_commenter();
    $req = get_option( 'require_name_email' );
    $aria_req = ( $req ? " aria-required='true'" : '' );

    $fields =  array(
    	'author' => '<p class="comment-form-author">' . '<label for="author">' . __( 'Name', 'domainreference' ) .''. ( $req ? '<span class="required">*</span>' : '' ) . '</label> <input id="author" name="author" type="text" value="' . esc_attr( $commenter['comment_author'] ) . '" size="30"' . $aria_req . ' /></p>',
    	'email'  => '<p class="comment-form-email"><label for="email">' . __( 'Email', 'domainreference' ) .''. ( $req ? '<span class="required">*</span>' : '' ) . '</label> <input id="email" name="email" type="text" value="' . esc_attr(  $commenter['comment_author_email'] ) . '" size="30"' . $aria_req . ' /></p>',
    	'url'    => '<p class="comment-form-url"><label for="url">' . __( 'Website', 'domainreference' ) . '</label>' .
    	            '<input id="url" name="url" type="text" value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30" /></p>',
);

    return $fields;
}
add_filter( 'comment_form_default_fields', 'wp_theme_t_change_default_comment_fields' );