These are all taken from the final game translation files. If they are exactly used like this I can't be sure of course, but it sheds some more light on what there is in store for us. Enjoy!
Gear Sets
Gear set equipment can be found by completing the most challenging activities in Manhattan.
Collecting and wearing gear sets grant powerful stat bonuses and talents.
Gear sets of varying gear scores can be found for many playstyles. Find the set that best suits yours.
“Tactician's Authority” – enhances electronics and support capabilities
“Striker's Battlegear” – provide bonuses for assault capabilities
“Sentry's Call” – enhances marksman capabilities
“Path of the Nomad” – provides bonuses for lone wanderers
Item trading
Items dropped by enemies can be shared with other players.
Trade items by dropping them as loot from your inventory, so players in your group can pick them up.
You can only share items for a limited amount of time after you have acquired them.
Items can only be shared with players who are currently in your group and who were also in your group when the item was originally dropped.
Daily and Weekly Missions
Global and Personal Assignments are automatically obtained when you log in and can be tracked from the map via the menu called “Mission Overview”.
Assignments are available for a limited time, after which, they will be replaced by different assignments.
Assignments come in four different categories:
Combat
Dark Zone
Crafting
Main Missions
Most assignments can be completed while playing alone but some will require enlisting other agents assistance to complete.
Supply Drops
Dark Zone Supply Drops are a global event where the Strategic Homeland Defense agency air drops multiple supply caches to assist Division agents.
Supply drops will occur multiple times over the course the day.
The supply drops will contain non-contaminated gear of all types that will be ready to use without the need for extraction.
These supply drops will be heavily sought after by other agents and enemy factions that roam the Dark Zone, so be ready for resistance.
Gear Score
Compare the Gear Score of the most powerful items in the game to know which one is the best. Increase your average Gear Score to gauge your chances against high end content and display your prowess in the Dark Zone.
Every non-vanity gear piece that can be found when your agent is level 30 has a Gear Score value. The higher an item’s Gear Score, the stronger the item.
The overall Gear Score of your agent can be seen in your main menu next to your player level. Gear Score indicates the advancement of an agent.
Other agents’ Gear Scores are displayed next to their health bars.
Improving your gear and increasing your overall Gear Score will grant your agent access to the most dangerous high end challenges. Your Average Gear Score can be found in the main menu and is visible to other players. It is the average value of all equipped gear pieces.
Challenge Mode
Play main missions in Challenge Mode with new encounter compositions and stronger enemies to receive high end rewards.
The challenge mode is now available in Lincoln Tunnel Checkpoint, Lexington Event Center, WarrenGate Power Plant and Russian Consulate.
You must have completed the mission once and have a Level 30 character before you can play challenge mode.
The encounter compositions are reshuffled to offer a new challenge and the amount of enemies is balanced for 4 players.
All enemies are now level 32 elites.

Dark Zone Supply Drops sound awesome!
As for gear sets, I don't know if I really like the fact that a full matching set gives bonuses. I'm worried this will lock us into certain sets for endgame.