As I wait for the next hour to get onto my server, I figure I may as well get to this instead of playing Space Invaders Extreme on my DS or Guitar Hero 3 on my PS2.
A battle cry is meant for a group, hero, army, etc, to improve morale. To bring a sense of unity when battle comes.
In the game, as we all know, whether we like it or not, the battle cry of the Horde is, predictably, 'For the Horde.'
Naturally, the junior hordelings will often scream this at the top of their lungs to show their exuberance for the bad guys (See the Spoiler Filled Wrath Gate Scenes and subsequent fight). I find it annoying, though, I can hardly blame them. When you want to rally your side to courage in actual warfare, you need something simple and effective to achieve the desired affect.
To expand a bit, 'For the Horde' is not as powerful as it once was. After all, after Wrath Gate, it should be noted that there are many Horde that would consider their kinsmen with much more suspicion. Furthermore, the only people that would say 'For the Horde' are orcs. The typical non-orc Horde member doesn't have the same history with it, since it dates back to, and is more related to, the Old Horde. (which, if recent events are to be believe, don't really differentiates itself from the so-called New Horde. The new Plague? Repeated attacks on Dalaran Mages? Poisoning Alliance Citizens? The list goes on.)
This goes double for the Forsaken and Blood Elves, who merely see the Horde as a means to an end, survival, not a means of friendship, since there's still bad blood between the BElves and Orcs since the latter was responsible for much razing of the forests of Silvermoon and considering how long these elves live, they don't forget things like that easily. Also, Forsaken are just a step above being a slave of the Lich King, by virtue of the fact the only thing that differentiated a Scourge from Forsaken was that the former wants to kill everything living, while the latter want to kill the undead AND everything living.
The only exception to this is the 'good' Forsaken that steals a precious gem from Sylvannas for the sake of preventing unleashing an ancient evil, but are hunted down and killed by Varimathras' decree. If there were more examples of these 'noble' Forsaken, who don't let the little fact that they're dead interfere with what they've always believed to be right and wrong, I would be a lot more sympathetic to their cause. In fact, I wish there were more of them, then I'd probably roll one instead of the usual “GRR! I R ANGRY! I H8 TEH LIVIN'!” archetypes you usually see.
But I digress...
The Alliance needs a battle cry. So, instead of going through the many possible ones that won't work, let's go through the one that will. (In my opinion.)
Yes, Anduin Lothar. The Lion of Stormwind. The Hero of the First and Second Wars. The man whom the child-prince of Stormwind is named after.
But wait, you say, wasn't Lothar human? A man who has never seen the forests of Ashenvale, the fields of Argus, or the halls of Gnomeregan?
Certainly! Because he had no home to call his own. True, he was part of the Brotherhood of the Horse, based in Stormwind before it was burned to the ground; however, the fact that he had no home to call his own was the very reason why he was chosen as the grand commander of the Alliance of the Second War.
Before the Grand Alliance came to be, the leaders of the Human nations were suspicious of each other for various reasons and felt to put a single person from any of these nations would put some political pressure on the others. King Terenas Menethil, however, seeing these petty squabbles, knew that unless they had a man that could lead them, while ensuring that there wouldn't be a civil war afterwards, wisely chose Lothar.
It makes sense for all the races of the Alliance to use his name as a war cry. He fought for the homes, the lands, and the lives of his people, since he gave all of himself for that and, sadly, never got the chance to see the fruit of his labors after being killed in a trap by the cowardly Doomhammer.
The Draenei and the Gnomes, without a home to call their own, can relate to Lothar, as he was one like them.
The humans can relate to him easily, by the fact their prince is named after him and his statue still stands in defiance in the Blasted Lands, pointing his sword to Blackrock Mountain.
The Dwarves also have an understanding of Lothar's character, since many of them fought beside them in the Second War, especially the Wildhammer clan, so they can vouch of him to Bronzebeard.
The Night Elves, though not losing as much as the Draenei and Gnomes have, can still relate to him, as their lands have been lost and are being stolen by, not only aggressive and savage orcs, but worgen, satyr, cultists, and naga as well.
So, there you have it, folks.
Or, if you're feeling sassy; F*** the Whorde.