I had to post quickly, I keep forgetting that I'm going to the other subway station and it is a bit further away.
MMO-Champion has posted the dialogue from Wrathion's 5.1 quests:
Alliance includes this bit -
We discussed the merits of your High King. I have been observing him closely.
It is true: he has the spirit of the wolf. And he fights like a wolf.
Having seen him in action, I now know what that means.
Wolves are pack animals.
Your King is calling his pack to him, assembling an Alliance in the truest sense of the word.
The Horde gets this -
Do you recall our earlier conversation?
We spoke of your Warchief. His inner conflicts and his outer conquests.
I asked you: Who is the soul of the Horde?
Your efforts on Pandaria's southern shores and elsewhere have given me my answer.
YOU are the soul of the Horde.
Your actions in the coming weeks will come to define your people.
It looks as if the Horde are going to be portrayed as individualists; if I recall correctly, we see something similar in the starting Monk quests. Although there are strong figures in the Horde, it might be hard for any of them to step up as a leader. Certainly, there would be endless flame wars among the players, no matter who steps up.
On the other hand, who is going to tell Wrathion no? The Aspects burned out their powers to defeat Deathwing, but how much power does his heir wield? For that matter, why is he in the expansion at all? We remember him as just an egg, but look at him tossing about legendaries now.
Don't believe me? Picture this:
WOW 6.x "Hi, I'm Wrathion and I'll be taking over here. Hey! Look at that! Balls of green fire falling from the sky! Get 'em!"