The vex dlc will probably end with us removing them from the solar system, for the time being, by destroying some major mind core in the depths of Venus or Mars, and now that we eliminated the vex and taken, who were the two races they are at war with on Mars and the dreadnaught, they will put all of their efforts into fighting us and we will most likely get a glimpse at the true power of the empire.

Then the level cap will be raised from 45 to 50 in time for Destiny 2. I stand by my other statements