The developer documentation says that the about the new api, that apps can receive and respond to events sent by external media players using Media Player APIs by using the MPPlayableContentManager class, to control the interactions between the app and the external media player. Here does the reference external media players points to another app's Movie player?
When an app starts, it loads a data source, either from the device or from a server, that contains the available media items and provides this information to the media player. The media player reads and displays this information to the user. This can be done with out the new api right? what advantages does the new additions make?
The media player interacts with the app by sending events that the app has registered for. The app responds to an event and changes its behaviour based on the event received.