Apple released Apple TV Software Update 2.3 late on Wednesday. The update added support for AirTunes so users can stream music from one Apple TV to another, or to an AirPort Express.
The version 2.3 software update also added the ability to use third-party remote controls with Apple TV, added the ability to view playlists that contain movies, TV shows, music videos and podcasts, and also added volume control in music.
The update is free and will appear during your Apple TVis regular software update check. To force the update to install ahead of the standard weekly check, navigate to to Settings > General > About > Update Software on your Apple TV.