The Big Bad in the new expansion is Deathwing aka Neltharion the Earthwarder once one of the 5 dragon aspects of Azeroth, corrupted by extra-terrestrial demons turned into a Magma filled adamantine plated nightmare hellbent on bringing the elemental plane of fire and all its associated fire elementals (spirits of flame much?) to bear on the mortal races, hence the title Cataclysm.
Nail a beard to it and put a cabinet in its main hand weapon slot and call it Captain Mayday imo.
As for the Dwarves themselves, there are three types in Warcraft Lore,
Ironforge Dwarves: the player race, certainly not cuddly, huge fans of alcohol, engineering, exploration and battle they have been on the front lines with the Humans since the greenskins portalled in and started destroying towns, cities and whole kingdoms, given a poor scottish accent, as a scot myself i would describe it as a North American approximation of a scottish accent.
Dark Iron Dwarves: in my opinion these are the closest to DF Dwarves, they live in the molten core of the planet, use golems, fire elementals and the magma itself as defense mechanisms, hellbent on the destruction of everything that doesnt have a beard, kidnapped the Ironforge Dwarven King's daughter got her pregnant and now have a claim on the Ironforge Throne.
Wildhammer Dwarves: i wish i was making this up, a clan of dwarves who have rejected the dark places in the earth for Gryphon Mounts, still huge fans of alcohol, they built their home on the mountains rather than under it, tamed flying beasts and use them to destroy their enemies. especially the Trolls they share a valley with.
The lore of the dwarves discovered during the Northrend Expedition to destroy the Lich King shows that dwarves began as the "Earthen" titan created servants to bring order to the chaos, infected with the curse of flesh by The Old God of Death Yogg-Saron and his Forgotten One servants, the upshot of this is self-determination of all the non-ancient mortal races (everything but the Trolls and Elves) was a side effect of the death god's interference with the Titan Pantheon's creations.
My opinion, there is more than one DF Player at Blizzard HQ.
Conclusion: if there is trouble the elves caused it, the humans made it worse and the dwarves were there to stick their axes in the kneecaps of the legions of demons, orcs and the very elements themselves that come boiling out of the fractures of reality, no catsplosions though, slackers!