My initial thoughts were that such density in Ironforge is not much compared to Vanilla or TBC high pop realms(1) from back in the day(2), and that latency is painful to watch. Then he went outside and that explained the latency and also represented probably the largest crowd I've seen in one place. I hope Morhaime and some of the other guys at Blizzard see this video.

(1)By calling it a realm instead of a server I suppose I out myself as a former WoW GM.

(2) Fairly typical player density early in Vanilla (in an atypical and hillarious situation): https://www.youtube.com/watch?v=CZ_WdYvwrDA