Please don your tinfoil hat - all that follows is speculation based on in-game evidence. It is not canonical lore endorsed by Blizzard.
One of the big reveals of Wrath of the Lich King is the Curse of Flesh. Upon our arrival in Ulduar's Halls of Stone, we escort Brann Bronzebeard to the Tribunal of Ages, a repository of Titan knowledge. After a fierce battle with the Tribunal's defense systems, Brann manages to access the Tribunal's information and learns the history of Azeroth, including how the Titans created Azeroth and how the Old Gods came to infest it, and how the Titan's creations of stone and iron were infected by the Curse of Flesh, making them more easily assimilated by the Old Gods. After defeating and imprisoning the Old Gods, the Titans re-engineered their creations to ensure they were no longer susceptible to the Curse... leaving the ones they'd already created to suffer it, and slowly change into the dwarves, gnomes, humans, troggs and their offshoots. Thus was Azeroth peopled in many cases.
It sounds plausible enough. But there are some problems with it - namely, not all of the Titans information sources agree with it. For instance, the first Titan trove accessed by the mortal races of Azeroth was in Uldaman, in the Badlands. This Titan complex, lying in the heart of the Eastern Kingdoms, is potentially the source of the dwarves and gnomes who live nearby in the mountains of Khaz Modan.
The Lore Keeper of Norgannon we meet at the end of Uldaman tells us that the Titans deviated from their normal plan when creating seed races.
What does this mean? Rather than the typical biomass construction foundation used by the Creators implies that the use of stone and other materials in the Titan constructs of Azeroth is not standard. This is not what the Titans usually do. Why did they do it on Azeroth, then? They appear to have done it quite extensively as well - the Earthen, the Mechagnomes, the Vrykul, the Mogu, the Tol'vir - a whole host of inorganic entities, using 'a cross-section of Azeroth's crust' to construct them. And why is the resilience of Azeroth's essence so remarkable?
A cross-section of Azeroth's crust was used as the foundation for the Earthen's synthesis rather than the typical biomass construction foundation used by the Creators.
Research on the world's composition led the Creators to theorize that an enhanced being could be synthesized that would epitomize the resiliency of this world's essence. This was accomplished by choosing to use a blend of Azeroth's various stone core compounds as the foundation.
One of the tidbits from this weekend's press interviews is the Fomor, a gigantic entity we'll encounter on Draenor who are ancestral to the gronn. We're told that they will be made of stone, three to four times larger than the gronn themselves, and with the ability to shape and control the earth beneath their feet. And this has me wondering - how are giant rock monsters ancestral to the gronn? Of course, I have a solid group on antecedents. The Vrykul. entities of rock and stone and iron, have flesh and blood descendents on Azeroth right now. In fact, we see a similar progression - larger inorganic vrykul transform over time into small (but still fairly large) flesh and blood vrykul, who themselves in turn become yet smaller beings, what we call humans. So this leads one to wonder - are the ogres similarly descended? Do the fomor degenerate into the gronn, who then degenerate into ogres? Are ogres the humans of Draenor... and if so, does that mean the fomor are Titanic in origin as well as size?
Of course, we don't know that Draenor had any Titans on it. We do, however, know that it apparently had, if not Old Gods on it, than certainly worshipers of the Old Gods. It also had plenty of elementals - and at least on Azeroth, when the Old Gods were present in force, they were easily coerced and dominated by the Old Gods to do their bidding. And the presence of the Cipher of Damnation (found in Shadowmoon Valley during our trip to Outland) implies that the same ability to bind and coerce elementals existed on Draenor, as well. And what's fascinating is, the Old God worshipers I mentioned? They were arakkoa, known as the Dark Conclave. They were found in Shadowmoon Valley (the same place the Cipher of Damnation was used to summon Cyrukh the Firelord) and they nearly managed to summon what appeared to be an Old God before Gul'dan wiped them out. And what's interesting about the arakkoa is, they had an ancient civilization known as the Apexis, who left behind crystalline devices that uplifted those entities that were exposed to them.
Did Draenor have at one time something akin to the Well of Eternity, this time made of crystal? The waters of the Well of Eternity and its sibling/offshoot, the waters of the Vale of Eternal Blossoms, had a similar effect to the Apexis Crystals. And this leads me back to Uldaman, and the Lore Keeper of Norgannon, and his explanation of why the Earthen were as they were.
Imagine, therefore, that on Draenor a synthetic matrix was used when seeding the world for a different purpose than the earthen, or vrykul, or mechagnomes, or tol'vir, or mogu. Each of these synthesis matrices has a specific purpose in the shaping of Azeroth, and were created with a resilient foundation made from that world's essence - ie the minerals of Azeroth. This implies that on other worlds, the Creators (Titans) used biomass. But it also implies that they were capable of modifying matrices on other worlds as well - nowhere does the Lore Keeper of Norgannon state that Azeroth was unique in using the planet's rocking foundation rather than biomass. Typically they used biomass, yes, but not exclusively. So imagine, then, Draenor, with its own unique properties, its Apexis crystals with their ability to change and elevate life, its elemental spirits and Old God cults... what kind of synthesis matrices would Draenor require?
It is one of the synthesis matrices the Creators use when seeding a world. Each synthesis matrix is used to achieve the Creators' goals. For Azeroth, a subterranean being matrix was modified to create a being with increased durability with an affinity for deep region shaping; the Earthen are the product of this modification.
There are giants on Azeroth, giants left behind by the Titans. Frost giants once served Hodir, one of the Titanic Watchers of Ulduar, and molten giants such as Ignis once labored under Loken, prime designate of the world of Azeroth. According to the Tribunal of Ages, these giants were known as the Aesir and Vanir, and Loken moved to place them in stasis to prevent their interference with the plans of his master, Yogg-Saron. While the giants of Azeroth still exist, their ability to organize and oppose Loken's treachery was greatly hindered. And this may have prevented them from falling to what the Tribunal and the Lore Keeper of Norgannon both called matrix destabilization, what we've come to call the Curse of Flesh. The curse that ravaged the Mogu until Lei Shen stole the heart of Ra-Den, and found a way to 'reverse-engineer' it, the curse that Deathwing showed the Neferset tol'vir how to escape. But on Draenor, no designate seems to have existed, or if it did or does, it did not place the fomor in stasis... and so matrix destablization began. They became smaller. Stone turned to flesh. In time, the race of ogres came to be... and in time, from brutish roots, geniuses with the power of magic rose.
And so we come to this - what if this is exactly what was supposed to happen all along?
We know that the Titans create seed races to inherit the worlds of their creation. We know that in most cases, these seed races are made of biomass, not the resilient foundation of the earthen and vrykul and others. These special constructions are made when there is a reason for them - a dangerous force or condition to be overcome, like the Old Gods. Both Draenor and Azeroth have similar conditions - elemental spirits, Old God activity, and the means to bind elementals in the Cipher of Damnation. The Cipher is enormously powerful - Gul'dan used it to sever his Draenor's orcs from their close ties with the ancestor spirits and elementals of their world, pulling Cyrukh the Firelord to Shadowmoon Valley and forcing it to wander enraged about the base of the fel volcano created by the Cipher's power unleashed. Khadgar heavily implies that it was another version of the Cipher that brought Ragnaros to Blackrock Spire. This means it's possible that the Old Gods taught it to Deathwing, who himself summoned Ragnaros to Hyjal.
So with elemental spirits and Old Gods and the presnce of the Apexis crystals, it could be that Draenor had need of resilient foundations of construction as well, and the Titans used the elements of Draenor in the creation of the fomor. Perhaps the ancient ogre war god Nath lurks in some lost Titan complex - in the southern continent or one of the islands? And perhaps other races come from a similar resilient foundation as well. Perhaps an ancient orcish ancestor race of stone, or other resilient materials - perhaps iron? Perhaps the true secret of the Iron Horde is how literally true that moniker really is. And perhaps they became as they are - perhaps the beings of Azeroth became as they are - not due to some horrific curse inflicted upon them by the Old Gods, who are notorious liars. Yogg-Saron controlled Loken for countless thousands of years, and Loken controlled the Tribunal of Ages. The Lore Keeper of Norgannon in Uldaman was safe, isolated, buried and lost to Loken's influence, but the Tribunal of Ages, the Halls of Stone, the Halls of Lightning, and Ulduar itself were all Loken's for the thousands of years he had to plan after he placed the Aesir and Vanir... the giants of Azeroth... in stasis.
So imagine that Loken seeks to control and mislead the Titan's creations. What better way to do so than to tell them that they were flawed, cursed? He simultaneously creates the impression that the Old Gods are more powerful than the Titans - after all, they can curse the Titans's perfect creations - and that the Titans have failed to anticipate this. Then he uses the creation forges to create new vrykul, new earthen... ones with elemental natures that would not degrade. This, despite the fact that the Curse of Flesh was supposedly imposed on the creations of the Titans by the Old Gods. If the Old Gods invented the Curse of Flesh, why does a change to the creation forge suddenly remove the possibility of it happening? Because the Curse of Flesh does not exist. It never did.
The synthesis matrices are intended to become biomass. The anomaly is simply that when Loken became dominated by Yogg-Saron, the Old Gods became aware of the process, and how to trigger it, causing matrix destablization ahead of schedule. The seed races were intended to defeat the Old Gods (as the mogu did to Y'Shaarj, proving it to be possible) and then they would undergo the transformation. This is why Ra-Den had no solution to the Curse of Flesh when the mogu demanded one - it's not a curse at all. It's exactly what the Titan's planned for them to do. Their attempt to prevent it is because their exposure to the Old God warped and corrupted their culture, because they learned to emphasize fear and control. Deathwing, as Aspect of Earth, understood how to 'remove' the Curse not thanks to the Old Gods, but because it was within his power to reactivate the subterranean being matrix, as it was of the earth.
On Draenor, this never occurred. Perhaps the fomor and other Titan synthesis matrices actually defeated and banished the Old Gods, explaining why the Dark Conclave had to try and summon one.
Of course, nothing is yet known. But we seem to be seeing on Draenor a different experiment, one rooted in the same basic ideas as Azeroth - a world with creations drawn from the essence of the planet itself, intended to safeguard a vast and terrible power against entities of corruption and malice. And the real difference may be in how well they succeeded. Because to them, flesh was not a curse, but a reward. They seeded their world.
While you don't need to have played the previous Warcraft games to enjoy World of Warcraft, a little history goes a long way toward making the game a lot more fun. Dig into even more of the lore and history behind the World of Warcraft in WoW Insider's Guide to Warcraft Lore.