WordPress 3.3 has a really nice new Help menu that can be used by plugin and theme developers to show a lot of helpful information to the users. It’s very similar to the Contextual Help Tab, but allows much more information to displayed in a more organized fashion. Instead of all content being displayed in a single pane, the new 3.3 help menu allows you to separate your help information into multiple tabs.
Note, in the official 3.3 release, the Help button has been removed from the toolbar, and has been restored to the Help tab in the top right.
Adding tabs to the WordPress 3.3 Help menu is not difficult, but works a little differently than the < 3.3 Contextual Help Tab, and is not backwards-compatible. Any helps tabs you have set up for WP 3.2.1 or earlier, will not show up in WP 3.3 (unless you used the add_contextual_help(), and nor will Help menu tabs setup in WP 3.3 show up in WP 3.2.1 or earlier. So you have to make sure that you go the extra mile and make your plugin help information accessible to users of WordPress 3.3 and earlier.