Before I say this I have to say I love this new feature... No wonder Blizzard continues to dominate the MMO market.
however Org and Stormwind are the only cities that are populated. I think this feature would work very well in places like;
Dalran, Shattrath, Ironforge, Darnassus, Thunder Bluff and Undercity as they are basically ghost towns.
It wouldn't really add much... but hey it would make the rest of the cities feel more like cities where you can chill and hang out when your not out in the world doing stuff...
Mists of Pandaria... Putting the "World" and the "War" back into World of Warcraft