It looks like I was wrong about Horde Paladins and Alliance Shamans being a joke. Too bad. While this move does solve the mechanical imbalance between the two factions, it does so in the least elegant way possible. (Not to mention that the whining has already started about racial abilities.) I'm kind of disappointed in Blizzard, and I still think that making the two sides less unique is a bad move in the long term.
However, a more interesting question is whether this move (and Blood Elves/Draenai in general) will solve the more pressing problem of numerical imbalance. In many ways, the Horde's biggest problem in raiding is lack of numbers. The Alliance has a much bigger pool of recruits to sustain the raiding guilds, and high end Alliance guilds have the option of feeding on lower guilds. But why is there an imbalance in the first place?
If you look at this article at PlayOn, you can see that the Alliance:Horde ratio stays fairly steady. However, there is a significant difference between server types. On PvE/RP servers, the ratio is 2 Alliance for every 1 Horde. But on a PvP server, the ration is 1 Alliance for every 1 Horde. Why is there such a difference?
I think the explanation lies in the Bartle player types. Killers are far more likely to roll on a PvP server. After all, their entire reason to play is to challenge and defeat other players, and PvP offers far more opportunity for that than PvE. So the difference in Alliance:Horde ratios can be explained with the theory that Killers are more likely to roll Horde than non-Killers.
This sort of makes intuitive sense as well. The Horde races project power. They are larger and more brutish. While not precisely evil, they are more likely to be the 'monster' races in other games. So it's kind of natural that a Killer would gravitate towards the Horde.
So why don't the non-Killers like the Horde? There are several possible explanations:
1. Alliance has better PvE racials that attract the Achiever. While this is true, it's very subtle, and really only raises it's head at level 60. As well, the ratios are very steady, and if this was strictly true, we should see the ratio for Alliance rising as more Achievers switch over. Instead, the steady ratio indicates to me that new players are making characters at the same ratio, before they really understand the mechanics.
2. Alliance races are prettier and do not project power. Perhaps non-Killers prefer playing prettier races. In the case of the Socializer, it may be deliberate to get away from Killers.
3. Non-Killers prefer to play the 'good guys'. Maybe a greater amount of people would prefer to what are normally the good guys, rather than the bad guys. As well, the Alliance has Paladins, which are viewed as extremely good characters.
It could also be a combination of things. As well, a lot of people simply follow their friends, so one person who feels strongly about race could influence the choice of a whole bunch of people. My first character was Horde, and I made it because an Achiever friend was playing Horde, and he made his because a Killer friend insisted on playing Horde. One Killer made a choice that dragged multiple Achievers and Explorers along.
But in any case, the important question is 'Can Blood Elves attract a greater portion of non-Killers to the Horde?'
I am not too sure of the answer. Blood Elves are clearly a 'pretty' race, so that may hold a greater attraction. But their racials appear to be more PvP oriented. And a greater mistake may be that they are evil in the mythos. They have paladins, but the paladins are 'evil' paladins (torturing an angel/Naaru and whatnot). If the motivator to play Alliance is to play the good guys, the Blood Elves don't help in that regard.
The problem is that it is fairly obvious why the Horde is more attractive to Killers. But it is less obvious why the Alliance is more attractive to non-Killers, and that will make a huge difference in whether the expansion numerically balances the two factions.
Personally, I would have made the Blood Elves an obviously 'good' race, and if they had paladins, to make the paladins truely good paladins. (The Lore, as Blizzard has proven, is fairly easy to manipulate.) At the same time, the Draenai could have been left as their original evil-ish selves. That way, the people who want to play the good side end up on Horde, in addition to the people looking at mechanics and racial looks.