Starting point class for Managing Orphaned Post Types in WordPress

orphaned-post-types.php

<?php
/*
   orphaned-post-types.php

   View the list at http://yoursite.com/wp-admin/edit.php?orphans=true

   In response to: http://lists.automattic.com/pipermail/wp-hackers/2010-November/035682.html

   Not yet complete.

*/

OrphanedPostTypes::on_load();
class OrphanedPostTypes {
	static $initial_post_types;

	static function on_load() {
		add_action('init',array(__CLASS__,'init'));
		add_action('admin_menu',array(__CLASS__,'admin_menu'));
		add_action('posts_where',array(__CLASS__,'posts_where'),10,2);
		add_action('manage_posts_columns',array(__CLASS__,'manage_posts_columns'));
		add_action('manage_posts_custom_column', array(__CLASS__,'manage_posts_custom_column'),10,2);
	}
	static function admin_menu() {
		add_menu_page('Orphans', 'Orphans', 'edit_posts', 'edit.php?orphans=true');
		add_submenu_page('edit.php?orphans=true','Manage Orphans', 'Manage Orphans', 'edit_posts', 'edit.php?orphans=true');
	}
	static function is_orphans($query) {
		global $pagenow;
		$is_orphans = false;
		if ( $pagenow=='edit.php')
			if (is_null($query->query)) {
				$is_orphans = !empty($_GET['orphans']) && $_GET['orphans']=='true';;
			} else {
				$is_orphans = !empty($query->query_vars['orphans']) && $query->query_vars['orphans']=='true';
			}
		return $is_orphans;
	}
	static function init() {
		global $pagenow;
		global $wp;
		if ($pagenow=='edit.php') {
			self::$initial_post_types = get_post_types();
	    $wp->add_query_var('orphans');
			self::register_unregistered_post_types();
		}
	}
	static function register_unregistered_post_types() {
		global $wp_query;
		if (self::is_orphans($wp_query)) {
			global $wpdb;
			$post_types = implode("','",get_post_types());
			$sql = "SELECT post_type FROM {$wpdb->posts} WHERE post_type NOT IN ('{$post_types}') GROUP BY post_type";
			$post_types = $wpdb->get_col($sql);
		  foreach($post_types as $post_type) {
			  register_post_type($post_type,array(
				  'label' => ucfirst($post_type),
			  ));
		  }
		}
	}
	static function posts_where($where,$query) {
		if (self::is_orphans($query)) {
			$post_types = implode("','",self::$initial_post_types);
			global $wpdb;
			$where = " AND
			{$wpdb->posts}.post_type NOT IN ('{$post_types}')";
		}
		return $where;
	}
	static function manage_posts_columns( $posts_columns ) {
		global $wp_the_query;
		if ( self::is_orphans($wp_the_query)) {
			$posts_columns['post_type'] = 'Post Type';
		}
		return $posts_columns;
	}
	static function manage_posts_custom_column( $column_id,$post_id ) {
		global $wp_the_query;
		if ( self::is_orphans($wp_the_query)) {
			switch ($column_id) {
			case 'post_type':
				$post = get_post($post_id);
				echo $post->post_type;
				break;
			}
		}
	}
}