Should explore the history of the Nine, who they are, is Xur the last of his kind, different dimension, different Galaxy, what role have they played with the development of guardians and the traveler, do they have a connection to the mystery guardian from year 1? We have already had the the vex, the hive(basically twice) and the fallen focused on. I know the cabal is the next obvious choice especially with mention of the emperor and how the cabal came to the dreadnaught. But it's fresh, and there are a lot of options that come with the nine, it's a clean slate for raids, strikes, stories and enemies, weapons too. This may be a hard one to do with an update because the size and scope of the story needed to make people happy(destiny players are really hard to please even though they play it non stop) would be tough to achieve with an download but it opens up a lot of options for the Destiny extended universe. Just a thought, love the game, been playing since day one, keep up the good work.