Once the Armory is retaken, it's filled with Shattered Sun guards, three new daily quests become available and several new vendors are spawned in the building. Dragonhawks, piloted by Kael's minions, circle the building, doing battle with the archers on the upper level. On the bottom floor, you'll find an ammo vendor, the only one I've been able to find on the Isle. Upstairs are several new "Exotic Gear Purveyors". This is where you'll find all the PvP gear available for Badges of Justice or T4/5/6 armor tokens.
The first new quest is another bombing run, but this time with an additional twist. "Intercept the Reinforcements" requires you to drops bombs on the sails of three ships in the harbor. After a quick fly over, you'll land on the middle ship and you must then defeat six of the enemies that spawn on the three ships. The respawn time seemed to be pretty short, so I was able to complete this one quickly, even with a lot of competition. The key here is to realize that you can swim over to the other two ships to find more spawn points. When you're finished, you can hop a ride back to the mainland near your original landing spot on the middle ship.
The second new quest. "Taking the Harbor", requires you to slay nine Blood Elves of three different types (hunter, warlock and paladin). It was odd to me that you only had to kill three of the hunter type elves, yet they seemed to have the most spawn points. They also appeared to have a deceptively large aggro radius, so you'll undoubtedly end up killing more of them than are needed for the quest. Regardless, this was pretty quick and easy, even with a lot of competition. Your targets are found all around the harbor and respawn quickly.
"Making Ready" is the final new quest that is available in this phase and it will likely hold the most interesting rewards. When this quest is complete, an anvil will be added to the Armory which will allow players to repair their gear (I haven't found any other NPCs with that function on the Isle) and will likely also allow the purchase of new Badge of Justice loot. In any case, the quest requires you to run over to the eastern coast of the Isle. Once there, you'll need to grab three keys off the large male Naga and use those keys to open the nearby chests (found near the Murloc huts) and collect the quest items found therein. For me, the keys had about a fifty percent drop rate and the Naga were plentiful. Again, another quick source of rep and income.
I was actually online when the portal to Shattrath was finally completed. A barely noticeable message appeared in the chat log that notified everyone of its opening. The portal will take you from A'dal's chamber in Shattrath to the upper story of the Sun's Reach Sanctum. The quest to open it, like all the other new dailies thus far, will still be available after the portal is complete.
The final stage of the Offensive promises new quests, vendors and apparently even a new title. At this point, we're only about forty percent through phase three, but I'll be sure to keep you updated as things progress.