The Division was one of the most ambitious titles shown at E3 this year. Much like Watch Dogs before it, it's an open world title that slightly changes the rules to accommodate a new gimmick. In this case, it's multiplayer where players don't even have to use a controller to play.
In the Gamescom trailer for The Division, Ubisoft has lifted the veil on its co-op mode that allows players on a mobile device to join a game with their friends. Ubisoft calls these mobile players "companions" and they are represented in the game as a UAV drone. From there, the player on the tablet can attack enemy fighters, heal allies, or even buff and debuff friendly and enemy combatants.
The best part about the new companion system is that the player on a tablet can play from anywhere. They don't have to be in the same room or even the same state to join in. It's incredibly ambitious and gives core gamers an excuse to bust out a tablet for something beyond Hero Academy.
As an aside, Ubisoft also used Gamescom as a venue to announce The Division for the PC. The team says that they're committed to providing a first rate PC experience, and Ubisoft's previous support of PC gaming (Uplay notwithstanding) leads one to believe that The Division will shine on the PC.