• Audio Playback: We now use GStreamer as our main media playback system across all platforms - this means higher performance, better reliability, and a platform for much more media-related functionality in the future.
• Album Art: The album artwork feature now supports drag and drop of images, as well as, the ability to toggle between displaying artwork for playing or selected tracks.
• Keyboard Shortcuts: We’ve cleaned up our keyboard shortcuts this release (and added some new ones for power users). Look for the link to a complete list of keyboard shortcuts in the application’s Help menu.
• Smart Playlists: By popular request we’ve implemented the ability to use a smart playlist as a rule within another smart playlist.
• Performance Enhancements: We’ve improved many aspects of the application performance. Most notably, importing media into Songbird is now 2-4x faster.

The RC1 release notes contain additional details about this build including a list of known issues.

As always, please file any issues, bugs, or crashes you find in Bugzilla so that we can address them before 1.0 final!