According to a Reddit post on the Destiny subreddit, took a snapshot of marketing posters from the next expansion of the game. With E3 just around the corner, Bungie is expected to make some sort of official announcement from it there.
Destiny expansions so far have included the Dark Below, House of Wolves, and the Taken King. Kotaku claims they have sources that can confirm the authenticity of the image. They said their source stated that the expansion will have a new raid, and be larger than the two year-one DLCs that we’ve seen so far.
Back in February of this year, Activision announced that Destiny was going to receieve a “large” new expansion in 2016, with Destiny 2 arriving in 2017. With E3 coming up in the next few weeks, it looks like we don’t have to wait too long to find out more details about this.