Destiny Expansion I: The Dark Bellow is now available for Xbox One
From the Major Nelson blog:
Content: Destiny Expansion I: The Dark Below
Check price and availability in your Xbox LIVE region
Game Description: Expand your Destiny adventure with a wealth of weapons, armor, and gear earned in new story missions, three new competitive multiplayer arenas, and a new cooperative Strike and Raid. Light Level cap raised to 32 and 5 additional Bounty slots added. New Cooperative Strike: The Will of Crota nests in the Cosmodrome. Three new competitive multiplayer arenas, Pantheon, Skyshock and The Cauldron. New Hive story missions that culminate in battles with a Hive god and his powerful minions. New Tower Character, Eris, with new Hive-themed weapons and gear to earn. New six-player Raid, “Crota’s End.