Current and Planned DLC

Currently in Destiny there are 2 planned DLC's as part of the expansion pass which gives both The Dark Below and House of Wolves. The Dark Below is already out while the House of Wolves is due for a May release. There are also 4 "Comets" as per the Bungie-Activison contract and these "Comets" are bigger expansions packs for Destiny coming out once per year.

The Dark Below

The Dark Below is a DLC in which the story follows Eris Morn, a Guardian who appears in the Tower now clearly drained of all her light and left in what appear to be a Hive transformation state. Eris Morn and her fireteam were on a mission to defeat Crota, Son of Oryx. They descended into the Hellmouth, home of the Hive on the moon, which they have claimed as their own. Eris is the only surviving member of the team that assaulted Crota. She has come to the tower to gather other Guardians strong enough to defeat Crota once and for all. She offers several bounties and as the player's rank increases with her she will also offer emblems, armour and some shaders. Along with Eris, The Dark Below adds hundreds of new weapons to the pre-existing vendors and some more that can only be obtained through loot. The Dark Below brings in its pack - 4 story missions, 2 strikes, 1 raid, 3 multiplayer maps and a new sparrow for people who downloaded the game. It also raises the level cap to 32

House of Wolves

Not much is known about the new DLC coming out but it is to be expected that it will rival The Dark Below in terms of content - hundreds of new weapons and armour, story missions, strikes and a speculated raid called Reef raid so far as well as more multiplayer maps and maybe even a light level increase (to level 34/35 this time?). What is known is that the DLC will come with the first Inferno Salvage match mode for multiplayer as well as accompany the other two newly introduced (When House of Wolves comes out) Inferno matches. A rumour also states that there will be a new social space opening up in The Reef to give guardians an alternative to the Tower. Hopefully this will also include more vendors selling the new armours and not just give the old vendors the new armour to replace the older stuff. Right now the Reef is an empty void in Destiny, nothing can be done there. The rumoured story revolves around The House of Wolves rebelling against the Queen of the Reef and winning their freedom back by spilling Awoken blood. A new Warlord rises. This will be exciting to see as it changes many of the relationships currently in Destiny. In might even have the House of Wolves controlling the entire Reef. Obviously apart from the Social space where I'd speculate the remainder of the Queen's forces will be held.

Comet: Plague of Darkness

The first of the planned bigger expansions. Nothing has been revealed about this project yet even the name might change before it hits the shelves. All we know is that this comet will land within or close to a year after Destiny's initial release September 9th 2014 as per stated in the Bungie-Activison contract 1 comet will come out every year within 1 year of the previous so that puts the first comet landing in before September 9th 2015.