One aspect of Android that has remained nearly untouched since 1.0 is its music player. Some would say Android's UI as a whole could use some polishing, but when it comes to the stock music player, I couldn't agree more.
You may recall Google's introduction of new features added to the Music app during this year's Google IO. Although none of those features are present in this leaked 3.0 version, one enhancement is quite obvious -- a very welcomed UI change. It's clean, colorful, and just looks great on the screen.
The leaked APK is a bit buggy, but it does work (kinda). The playback is a bit choppy at times, and force closes weren't absent. But it offers a pleasing look at the new UI enhancements. If this is where Android's UI is going in future versions -- I dig it.