Here are the keys things that many of us have noticed. If you navigate away from an application and come back, the application will not only pick up where it left off, but it will do it quickly and efficiently.
Pressing and holding the back button launches the UI, though we did not see a demo of killing apps.
It also seems that third-party music apps can be controlled using the playback controls which appear at the top of the screen when the volume buttons are pressed.
More in the video clip, caught below…