Lot more NPCs at the Harbor. Also a flight point of sorts. You can take a flying tour of the harbor at least for now.
Trade was warped in Orgimmar as people tried to find Thrall for quests and such.
Trade was also fun in Stormwind before the event started the first time. The King was in two places at once. His throne and at the Harbor. I think I was there for the first event because not everything happened like it did in later events. The ending call wasn't there from the King. Or at least it seemed that way. There were tons of 70s present an hour before hand. I went to try to kill a Horde Raid that was happening in Goldshire and then Westfall (not real successful...they were probably an Arena Team since none of the responding Alliance 70s could do much to them). They eventually left (probably when the event started in Orgimmar). Our Raid group tried to track them down, but instead went back to Stormwind and stopped a few other Horde 70s that were attacking from the front gate...then the Wyrms ad Horrors arrived...everything else stopped PvP wise. I imagine this will go on until Thurdsay.
Too bad you don't get much for killing these things. All I was getting was a tiny bit of Argent Dawn reputation (4 and 5 points per kill). I even managed to tag one of the Horrors in Orgimmar with my 40 priest and still only got 4 rep with the Argent Dawn and no experiance (I only hit it with Shadow Word Pain....the guards and other people killed it)
The Wyrms tend to fly too high to be hit by much. They come down from time to time to attack guards and people. As seen in the image I was using Chaos Bolt at times because it had a quicker cast time when they were outside of 30 yards. (In the image though it came into 30 yard range just as I got the bolt off. DoTs followed quickly.)
Images from Arygos US server.
Spoiler for Images of World Event:
Orgrimmar under attack
Let Chaos (bolt) Reign
Evade Bugged but shows what you'll be up against.
