Index: wp-settings.php
===================================================================
--- wp-settings.php	(revision 13166)
+++ wp-settings.php	(working copy)
@@ -733,7 +733,22 @@
 
 $wp->init();  // Sets up current user.
 
-// Everything is loaded and initialized.
+/**
+ * Most of WP is loaded at this stage, and the user is authenticated. WP continues
+ * to load on the init hook that follows (e.g. widgets), and many plugins instantiate
+ * themselves on it for all sorts of reasons (e.g. they need a user, a taxonomy, etc.).
+ *
+ * If you wish to plug an action once WP is loaded, use the wp_loaded hook below.
+ */
 do_action('init');
 
-?>
+/**
+ * The purpose of this hook is to fire actions once WP, all plugins, and the theme,
+ * are fully loaded and instantiated.
+ *
+ * AJAX requests should use wp-ajax.php and wp-admin/admin-ajax.php instead.
+ * 
+ * @since 3.0
+ */
+do_action('wp_loaded');
+?>
\ No newline at end of file