Grunt

Grunts are the first and last line of the Horde's defense. These powerful fighters arm themselves with mighty battle-axes and display all of the savagery and cunning of their race. In past generations, Grunts were characterized by their depravity and brutality. But now, under the visionary leadership of Thrall, the Grunts more closely resemble their savage, yet noble ancestors.
Abilities:
Pillage: Each attack that does damage to a building also gains resources. This is a passive ability. Pillage returns half the cost of the building if you destroy it at full health.
Enraged: The Grunt gains the ability to deal more damage as he loses more hit points.

Troll Batrider

The Horde frequently uses troll batriders, which are light flying units, on reconnaissance missions. Expert at riding and caring for their special steeds - vampire bats - troll batriders are perceptive and dangerous foes. In battle, troll batriders use their flying mounts to swoop down upon enemy targets. When fighting alongside the Horde, batriders are often equipped with blazing torches and fire bombs with which they can set buildings and other devices ablaze. These trolls wear simple leather vests of deep blue, studded with the teeth of various creatures, covering their lean bodies, leaving their taut muscles of their pale, sea-hued arms exposed. A thick belt around the creatures' waist holds several axes as well as a simple black scabbard with a short but wide sword. In wartime, the Horde sends batriders on missions against specific enemy targets. A well-equipped flight of batriders can wreak havoc and leave a trail of blazing buildings and dead people behind them. When targeting soldiers, batriders concentrate their attacks on lone warriors and small groups, preferring to swoop down on their targets and throw axes rather than engage them on the ground.
Abilities:
Unstable Concoction: Causes a powerful explosion that deals massive damage to a target air unit and also damage to nearby air units. Using this ability destroys the Troll Batrider.
Liquid Fire: Flings a volatile liquid that causes buildings to take damage over time. Buildings that are currently taking damage from Liquid Fire cannot be repaired and have their attack rate reduced.
Regeneration: Increases the hit point regeneration rate of Troll Batriders.

Orc Raider

Raiders were once considered to be the most honored warriors of the Horde. Yet, just prior to the Second War, Gul'dan the Warlock masterminded the disbanding of the Raiders. Now, after many long years, the young Warchief Thrall has decided to train a new generation. These mighty warriors carry hefty warblades into combat and rely greatly upon the cunning and ferocity of their faithful Wolf mounts to defeat their enemies.
Abilities:
Ensnare: Causes a target enemy unit to be bound to the ground so that it cannot move. Air units that are ensnared can be attacked as though they were land units.
Pillage: Each attack that does damage to a building also gains resources. This is a passive ability. Pillage returns 50% of the cost of the building if you destroy it at full health.

Tauren Kodo Beast

The colossal kodo beasts of the Kalimdor plains proved to be valued allies of the Orcish Horde. The mighty beasts were charged with carrying the Tauren's pounding war drums into battle. The huge kodos, serving as symbols of Tauren might and valor, also use their enormous size and strength to aid the Horde in battle.
Abilities:
Devour: Consumes a target unit, slowly digesting it and dealing damage per second to it. If the Kodo Beast is killed while the consumed unit is still being digested, the unit that was devoured will pop out.
War Drums: All friendly units within the aura's area of effect have their attack increased.

Wyvern Rider

The sentient Wyverns of Kalimdor were eager to ally themselves with the Shamanistic Horde. Impressed by the Orcs' commitment to honor and victory, the Wyverns allowed the Orcs to ride them into combat against those who would disturb the tranquility of Kalimdor and its denizens. The Wyverns, who share a common ancestry with both Dragons and Gryphons, use their powerful talons and razor-like fangs against both airborne attackers and ground troops.
Ability:
Envenomed Spears: Adds an additional poison effect to the Wyvern Rider's Attack. A unit poisoned by the Envenomed Spear takes an additional damage per second over time.

Tauren Spiritwalker

Spiritwalkers have a powerful connection with tauren ancestral heritage. Capable of channeling ancient tauren heroes, these champions of the spirit are valued in tauren society for the wisdom and history they carry within them. Tauren also fear the spiritwalker as a potent sign of the coming age; while many of this powerful race look upon the spiritwalker with some apprehension, the spiritwalkers still receive respect from their brethren. Tauren ancestors dwell deep within the Emerald Dream. The energies of that plane change the spiritwalkers pelt to pure white over time (though some are born with white pelts, destined to walk the path of spirit).
Ability
Spirit Link: Links 4 units together in a chain. All units with Spirit Link on them will live longer, by distributing half the damage they take across other Spirit Linked units.
Disenchant: Removes all buffs from units in a target area. Deals damage to hostile summoned units.
Ancestral Spirit: Raises a fallen non-Hero Tauren from the dead. The Tauren is revived with all of its hit points restored.
Ethereal Form: Turns the Spirit Walker ethereal, making him immune to physical damage, but unable to attack. Ethereal units can only be harmed by Magic attacks and spells.

Troll Witch Doctor

Although they are savage and nefarious in the extreme, the Troll Witch Doctors have aligned themselves with the Horde out of pure necessity. These dastardly magic users are adept at manipulating the chemical processes within their fellow warriors in order to augment their combat abilities.
Abilities
Sentry Ward - Summons an invisible and immovable ward that provides vision in an area. Can see invisible units.
Stasis Trap - Summons an invisible and immovable ward that stuns enemy units around it. The trap activates when an enemy unit approaches.
Healing Ward - Summons an immovable ward that heals nearby friendly non-mechanical unit's hit points per second.
Regeneration - Increases the hit point regeneration rate of Troll Witch Doctors.

Orc Shaman

Under the leadership of Thrall, the Orcs have rediscovered their ancient Shamanistic traditions. In an attempt to rid the Horde of its demonic corruption, Thrall banned the use of Warlock magic and necromancy. Now, all Orc magic users practice Shaman magic which draws its power from the natural world and the elements.
Ability
Purge - Removes all buffs from a target unit, and slows its movement speed. Purged units will slowly regain their movement speed over a short duration and also deals damage to summoned units. Purge does not slow friendly units when used on them and causes units to stop for a brief moment when first cast.
Lightning Shield - Forms a shield of electricity around a target unit, dealing damage per second to units around it.
Bloodlust - Increases a friendly unit's attack rate and movement speed.

Horde Unit List

Peon
Grunt
Troll Headhunter
Raider
Troll Marauder
Tauren Brave
Catapult
Tauren Kodo Beast
Shaman
Troll Witch Doctor
Tauren Spirit Walker
Wyvern Rider
Troll Bat Rider
Tauren Stormbringer - new unit!
Dreamweaver - new unit!

9 down, 7 more to go...

After a long day of posting Alliance units I think I'm gonna take a break and probably post units from another faction - most likely the Horde.

But back to the Alliance and future units. I think the hard ones to create for the Alliance are going to be the human valkyrie and the draenei dimensional ship. The valkyrie is a human flying unit (I don't know what the mount is going to be) that specializes in destroying magic based units. The Draenei Dimensional Ship is going to be a giant flying fortress that will bring the Alliance's aerial forces on the same par as the Undead's Frost Wyrm and the Sentinel's Chimaera. Also figuring out the special abilities for the Elekk Rider is gonna be a toughie. Stay tune for more.