Comet was the name of the huge dlc expansion set to take place after house of wolves. This was data mined some time ago and is obviously subject to change. It was rumored to obtain new exotics, as per usual, along with the mysterious 5th race, our possible 3rd subclass, and loads of content. However, no news has recently surfaced except that bungie has somewhat announced "Destiny 2" and that it will import our current guardians. Speculation also dictates that this possible game is the comet update yet it was so large it was made into a new disk. Of course, this is still all speculation until bungie gives us solid statements regarding both of these topics. Side note. Bungie also trademarked a new game title with an immense story and character depth and background which could meen many things. Feel free to look all of this up for your own judgment.