Harmonix, MTV Games, and Electronic Arts have announced that Rock Band Unplugged, a PSP game developed by Backbone Entertainment, has shipped to retail across North America and Europe. Rock Band Unplugged features 41 songs on-disc that encompass popular tracks from the Rock Band music library, as well as nine songs exclusive to the game for a limited time before becoming available as downloadable content on other console versions. Press 'read more' for details.