I have also noticed that the Lock screen shows notifications now. If you have new messages, they may show below the slide to lock area.

In the media player, when listening to songs and you go back to the album list, you can get back to your song by pressing the new play button in the bottom right corner. If your song is currently playing, there will be a revolving swirl around the play button. I used to have to restart the song if I exited because I didn't see a way to get back to the active song.

I will post more info as I come across things. Feel free to ask questions.