Something that people always complain about is the exclusivity of plate gear with Intellect stats, since only one specific class/spec combination in the game can use them. And it's a valid complaint! Gevlon recently inspected the breakdown of Intellect plate versus Intellect cloth.
Now, I don't entirely agree with his stance on the emotional effect of receiving loot, and his numbers aren't perfect, since he doesn't differentiate between Spirit and non-Spirit cloth, which is a crucial distinction. That being said, his results still show that the amount of healing plate is out of proportion compared to healing cloth, when considering how many spec/class combinations can use them.
Blizzard doesn't seem very interested in changing up this exclusivity. Which is a shame, considering the perfect solution is right under their noses:
Unholy Death Knights as an Intellect-using, plate-wearing caster DPS class.
Not only would this give us another class that could actually use Intellect plate, it would also add a unique flavor to WoW's first Hero class. It's not really that far-fetched, either - Death Knights are already half-caster anyway, especially Unholy Death Knights, with their heavy focus on diseases and magic damage.
And what many people may have forgotten (or never knew to begin with) is that the original Death Knights actually WERE spellcasters! None of this melee nonsense - the first Death Knights, those created by Gul'dan during the Second War, were undead spellcasters who used diseases and dread necromancy to battle their foes. They were the Horde equivalent of the Alliance's Mages.
A Warcraft II Death Knight. Artwork by Chris Metzen.
Unlike the Lich King's mindless Scourge minions, these undead creatures retained their intelligence, independence and terrible magical powers, making them some of the Horde's most feared soldiers during the Second War. They rode around the battlefield atop undead mounts, wielding truncheons that gave them incredible necromantic and elemental powers. (Essentially what Runeblades are to today's Death Knights.) Adding to their nightmarish presence was the fact that they were actually the corpses of human knights, reanimated and infused with the souls of dead Orc Warlocks.
Terrible powers of disease and decay; the ability to raise your dead comrades and use them against you; the necromantic shells of former allies, twisted and corrupted for evil purposes...it's no wonder the Alliance was so terrified of these abominations.
We've already seen one "old school" Death Knight in WoW, Teron Gorefiend. He's a raid boss in the Black Temple, but he's also involved in a very fun questline in Shadowmoon Valley, where you inadvertently free him from his eternal prison by retrieving his lost equipment. (Whoops.) In the quest Teron Gorefiend, I am, there is a very cool moment where Gorefiend's spirit possesses your body, and you have to fight his ethereal Draenei jailer using Gorefiend's abilities. These include well-known favorites such as Death Coil and Death and Decay, spells used by both the original and current Death Knights.
Teron Gorefiend. Artwork by PhillGonzo, WoW Trading Card Game: "Gorefiend, I am"
So how would my redesigned Unholy Death Knight work in WoW? Well, I'd want it to feel very different than a Warlock, since they share some similar flavor. It would be silly to have them simply be Warlocks in plate. At the same time, wielding "evil" powers such as diseases and decay is an integral, iconic theme to the class, so those would have to stay as well.
One of the major differences between a Warlock and a Death Knight is the fact that Death Knights use necromancy, not Fel magic. So why not emphasize this? My Unholy Death Knight would be a pet class unlike any other pet class - they wouldn't have a "fire and forget" pet like Hunters, nor would they limit him/herself to one powerful minion. Instead of having a strong single partner that they work in tandem with, my Death Knights would raise multiple undead allies to fight for them, and swarm/overwhelm their foes. Think Army of the Dead, but as part of your regular rotation. And there's no cute "Pebblemuncher" or "Dirtgobbler" names here, oh no. These ghouls aren't pets to be loved and adored - they're weapons, animated bags of disease and death whose only purpose are to savage your enemies and drag them into the grave.
Maybe they would even work tactically - the more ghouls you had raised, the more lethal your diseases would became, stacking and dealing more damage with each ghoul disease carrier? Or perhaps your diseases would serve a dual function - DoTs on enemies, but beneficial buffs when on your undead minions! I envision a handful of ghouls attacking a boss, the Death Knight spreading diseases from the boss to each of the ghouls, increasing their damage dealt, then dropping a Death & Decay on the entire pack, spreading more damage and disease everywhere.
I think the idea of using your spells not to directly deal damage, but rather to buff and bolster your minions could be an interesting play style, while still keeping true to the current Unholy spec emphasis/reliance on your pet.
How about specific moves? I imagine most of the Death Knight abilities involving ruthlessly sacrificing his or her ghouls to do cool things, such as bringing an ally back from the dead, exploding a ghoul in a massive burst of disease damage, vanishing only to erupt out of a faraway ghoul (essentially using it as a one-way teleport), etc. Or how about an effect similar to a Fire Mage's Combustion, only the strength of the new periodic effect would instead be based off the number of diseased ghouls sacrificed. Or in PVP, maybe a Death Knight could give up a ghoul's damaging abilities to instead have it cling to/slow an enemy, much like Gormok's Snobolds would batter players in Trial of the Crusader.
Essentially, my Unholy Death Knight would be a puppetmaster, dragging foes down under the weight of a dozen undead claws, all while horrible diseases rotted them away, empowering the Death Knight and his minions even further.
ALL YOUR INTELLECT PLATE BELONGS TO GOREFIEND!