Originally Posted by
Javox
If we ever get subraces, they'd need to fit lore and make sense. I think they'd need to be races that we are already friendly with and don't require an explanation for why they're now playable. That being said, some sub-races would need somewhat different racials if it makes sense and possibly even different classes. Like a high elf wouldn't have warlocks available if they were put with humans. Some races would need to start in different zones as well. A wildhammer dwarf wouldn't start out in the snow like the ones we have now.
Alliance-
Humans: high elves, half elves. Half elves exist, there isn't a doubt about that, and since they're half human, they are the most logical human subrace. High elves would only fit as a human sub-race. They are Alliance aligned, so they wouldn't fit as a blood elf one unless they start out in a phased Quel'Thalas. They also wouldn't fit night elves because I'm pretty sure they still aren't on great terms and it wouldn't make sense for them to start out in Teldrassil anyway. Elwynn Forest makes sense as most high elves are in Dalaran or Stormwind now and we can't start out in Dal, so SW it is.
Dwarves: wildhammer, dark iron. Wildhammer dwarves have been aiding the alliance since the Second War. We didn't really see them until Cata in-game, but they are firmly Alliance and the most logical dwarf subrace. Dark iron make less sense than the wildhammer as most of the time we see them, we're killing them for quests and dungeon loot. But with Moira's seat in Ironforge, them being playable isn't that hard to see. And like I said above, both of these would need a different starting zone. I'd say Hinterlands and then Burning Steppes.
Night elves: highborne? This is one that Blizzard would need to go a little farther with. We already can sort of make our characters look highborne-ish, so they might require a semi-different model.
Draenei: broken I'd say lost ones too, but I feel like they might be a little too far gone. But the broken would make sense as a sub-race. They would be one of the sub-races that would require a few class restrictions as they wouldn't have priests or paladins.
Those are the only Ally races I think should get them. Mechagnomes and leper gnomes seem cool, but I'm not sure how viable a leper gnome is going to be to any army or anything, and the mechagnomes would require more lore to explain why they have free will and whatnot.
Horde-
Orcs: Mag'har, Mok'Nathal? The Mag'har orcs certainly make sense and I'd like to see them playable. As for the Mok'Nathal, they would work as well, but I think that they'd work better as a means to give us our "ogre" race. Ogres themselves are too big and stupid (at least the Azeroth ones), but the Mok'Nathal are more intelligent. Neither of these would start out in Durotar though.
Trolls: forest troll, ice troll The forest trolls make the most sense. They helped the Horde in the Second War and it wouldn't take too much story to explain why they're walking around Org. The ice trolls would need a little more story to go along with it, but I think it would work. Once again, they wouldn't start in Durotar.
Tauren: taunka We interacted well with these guys in Northrend and they are the only tauren sub-race that I think would work. The yaungol seem to be too much the "bad guys". It'd need a lot of explaining. They'd start somewhere like Borean Tundra or Dragonblight.
Forsaken: elven forsaken Arthas plowed through Quel'Thalas just like he did Lordaeron. It'd only make sense that some of the forsaken were elves in life.
Then the goblins have hobgoblins, but I'm not sure they are intelligent enough to be viable. The sub-races of blood elves aren't exactly friendly to us (darkfallen, felblood, wretched), so they wouldn't have one.