Good stuff! I like it. Not sure how the Now Playing / Control on the menu screen would work. Maybe smaller. Just enough to see the track name and if you touch it you will get back to the media screen. Just thinking about how the display of plugin/applet icons will be affected. And in keeping with the Android thing, some little dots near the top or bottom of the menu screen to show which page of items you are on.
I like the layout of the media screen also. I would probably make the right/left sides only 1/2 the screen and show album art on the right. Use top bar to scroll track title, artist, album. Use the left for controls and media library navigation. A couple buttons "Track", "Artist", "Album", "Shuffle" in the control window will product the desired list on the right, if idle it would revert back to Now Playing with the album art.
While a list of media is in the right window, there could also be some alphabet tabs to jump to the appropriate part of the list.
These are just my ideas. You are, of course, not obligated to implement these