Check out this video of the next Android music app. This app didn't make it into Gingerbread, but it looks like Google is working on a new UI for Android 3.0. The new app is not quite ready for prime time as it is buggy, and doesn't have a lot of new features. The biggest deal at this point is that it is aesthetically different than the current app.
Earlier this year at Google I/O, Google demoed a new music app that was supposed to include features that let you push web-purchased songs to your device, and allowed you to browse your PC's music library from your phone. This leaked app doesn't have any of those features yet, but keep your fingers crossed.