Apple DVD player application for OS X has been updated to version 3.1.1. The new version includes enhanced features and new abilities. From Apple:
DVD Player 3.1.1 adds features for DVD authoring, including the ability to select and play the contents of a iVIDEO_TSi folder from a local volume. This update also adds AppleScript support for selection and playback of DVD content. A Script menu makes it easy to add and run custom scripts. Also new is a iwidei layout for the info window and various stability enhancements.
You can get the update via Software Update (in your System Preferences app found in the Apple menu) or download it directly from AppleCare.