On December 9th, Destiny's first expansion, The Dark Below, will add several new features as well as new story content.
The Dark Below will feature new gear, five more bounty slots, and a light level cap increase to 32, as opposed to 30.
The new story content will focus on the Hive god, Crota. A new character will appear in the tower as well, Eris, who will give you these new story missions.
There will be a new strike called the Will of Crota, as well as a new six man raid called Crota's End. There will also be three new multiplayer maps. Playstation fans will get a timed exclusive strike called The Undying Mind. This will open up to Xbox users sometime next Fall.
The DLC will be $19.99 or you can get it as part of the expansion pass that costs $34.99 for 2 DLC packs.