If We Get New Races...

Races are far easier to fit into WoW than classes, but as Mists of Pandaria showed us, Blizzard is willing to put both in if it fits with the flavor of the expansion. While I have my fingers crossed for Demon Hunters (as I have pretty much since the Cataclysm announcement - I like Death Knights more than Demon Hunters, so I was blown away when they were announced way back in '07, but DHs are a close second,) I'd also be curious to see if we got a new race or new races.

It's possible they'd go the Pandaren route and simply make another "neutral" race, though I think going to this well too many times threatens to dilute the factions.

While there would be several logistical issues with making Naga a playable race (mostly revolving around their lack of legs or feet,) the other question is who we would get to counter-balance them on the other faction.

If we assume Naga would be made available to one side or the other, which would it be?

First off, we have to wonder whether the Naga are inherently corrupted, or if they are simply following Azshara due to her charisma. If it's the former, you could maybe stretch it and allow them to join the Horde, but even then you'd need some kind of redeeming "break" from their corruption, similar to the way the Forsaken broke off from the Scourge.

The Naga are also likely to have some deep-seated resentment (and vice versa) with the Night Elves, which would make it tough to get them on board with team blue. On the other hand, they likely have a lot of commonality with the Blood Elves, and are probably even related, given that both are descendants of the Highborne. There's even precedent of Blood Elves and Naga working together, albeit under the command of Kael'thas Sunstrider, whose stock kind of took a plunge after he aligned himself with the Burning Legion.

Still, I'd have to say that the Naga make more sense as a Horde race than an Alliance one. That said, the Pandaren make more sense as an Alliance race than a Horde one, and that didn't stop them from making them available to both.

Should we get a Naga-focused expansion, the Naga would share the center-stage focus the Pandaren did in Mists, which of course would make whichever faction didn't get them feel cheated, so that might be enough to make Blizzard give them to both. On the other hand, making the Pandaren neutral made a lot of sense for them as a culture. Pandaren are easy-going, and would not want to pick sides. The Naga, however, are anything but easy-going, and they would absolutely pick a side and then fight viciously in its favor.

Now, that said, you could of course have the Alliance and Horde factions within the playable Naga have a much more bitter rivalry than that of the Tushui and Huojin. There might even be an ongoing conflict between them and they actually enlist the aid of the two factions to fight each other, offering their services in exchange for said aid.

But if we assume that only one faction gets the Naga, what else would fit?

Ogres:

Admittedly, Ogres don't really have much to do with the South Seas, but they're such an established part of the Horde's history that it's kind of surprising that we haven't seen them as a Horde race already. There's certainly precedent for Ogres serving the modern Horde in Feralas and Dustwallow Marsh.

Kvaldir/Vrykul:

The Vrykul were probably a kind of one-and-done race for Wrath of the Lich King, but I think they're really cool, having a more direct tie to the Titans. The Kvaldir in particular would make sense as a presence in an ocean-faring expansion. While we tend to associate them more with the icy waters around Northrend, we certainly saw them (or at least saw the memory of them) in Vashj'ir. The Kvaldir appear to serve Neptulon, and would likely be very motivated to strike against Azshara. The Vrykul/Kvaldir might also be more inclined to join the Alliance, given their shared heritage.

Murlocs:

Mrgrgmgrl? Mrglgrmrl! No but seriously, this could potentially be awesome, or it could ruin murlocs. Still, they'd fit in a Naga expansion.

Arrakoa:

Honestly, Warlords was probably the best opportunity to add Arrakoa (and Ogres, really) as playable races. We'll be leaving their world behind, so... probably not.

Furbolgs:

Not really South Seas inhabitants, but the Furbolgs would make sense as an Alliance race, though I imagine they'd basically look like brown Pandaren - though perhaps a bit more muscular and leaner.

Ethereals:

Cool? Yes. Tied to a South Seas/Azshara expansion? No.

Something Totally New:

Of course, there's a possibility that Blizzard could just come up with something we've never seen before. It'd be risky, though. Every playable race has had some precedent before they were made available. In fact, every playable race was present in the RTS games except the Worgen, and they were introduced in Vanilla and are also tied to a typical fantasy creature - the werewolf - so there wasn't much to explain.

While I wouldn't rule it out, I actually think there's a good chance that we won't get new races with this expansion, especially if we get a new class. Naga would be cool, and if we really do get an Azshara expansion, this would be the time to do it. I'd also love for them to go back and apply the facial mapping tech they developed for the Pandaren to the Worgen and Goblins.

Again, though, this is all up in the air until Thursday. Even though all the rumors point toward it, there's a substantial chance that we won't even have a South Seas expansion next.