NiGHTMARE

One of the (most likely unintended) benefits of the Essentials style classes is that it's much quicker & easier to come up with your own homebrewed builds, or even entirely new classes. Here's a quick attempt at an Essentials version of the warlock (an official one will be appearing in Heroes of the Forgotten Kingdoms). Like the previews, I've only described the 1st level features . 3rd Edition players should notice the reintroduction of a couple long-lost class feature.


Theurge

Arcane Striker

Key Abilities: Charisma; Constitution or Intelligence

Class Traits

Hit Points: You start with hit points equal to 12 + your Constitution score. You gain 5 hit points each time you gain a level.
Bonus to Defenses: +1 to Reflex, +1 to Will
Healing Surges per Day: 6 + your Constitution modifier
Armor Proficiencies: Cloth, leather
Weapon Proficiencies: Dagger, hand crossbow, shortbow, short sword, sling
Implement Proficiencies: Rods, wands
Class Skills: Arcana (Int), Bluff (Cha), History (Int), Insight (Wis), Intimidate (Cha), Religion (Int), Streetwise (Cha), Thievery (Dex)
Trained Skills: Four from the list of class skills

THEURGE HEROIC TIER

Level 1 - Eldritch blast, Eldritch Essence, Eldritch Pact, Prime Shot, Warlock's Curse
Level 2 - Theurge Implement Talent, Shadow Walk, Utility Power
Level 3 - Boon encounter power
Level 4 - Ability score increase, Extra Eldritch Essence
Level 5 - Eldritch Shape
Level 6 - Utility power
Level 7 - Boon encounter power, Extra Eldritch Essence
Level 8 - Ability score increase
Level 9 - Improved Pact Boon
Level 10 - Utility power

Level 1: Eldritch Blast

(Same as Player's Handbook, except damage dice are d6's instead of d10's)

Level 1: Eldritch Essence

As a warlock, you do not use at-will spells in the same manner as other wielders of arcane magic. Instead, you possesses a repertoire of abilities known as eldritch essences, which allow you to modify your eldritch blast in a wide variety of ways - from increased damage, to different damage types, to penalties.

Benefit: You gain two of the following powers of your choice



Level 1: Eldritch Pact

(Same as Player's Handbook, except it doesn't determine your at-will power; instead, it determines your encounter powers)

Level 1: Prime Shot

(Same as Player's Handbook)

Level 1: Warlock's Curse

(Same as Player's Handbook)

Also note that the planes have been radically reshuffled in 4th edition D&D. The ethereal plane and positive energy plane no longer exist, the outer planes are now all domains/planets in the astral sea, the elemental planes have been lumped into a singular plane called the Elemental Chaos (which also incorporates the Abyss), the plane of shadow and the negative energy have been merged together to become the Shadowfell, and the former demi-plane of faerie is now a full plane known as the Feywild. The Feywild and the Shadowfell are "sideways" to the campaign world (both being distorted echoes of it), while the Astral Sea is "above" the world, and the Elemental Chaos is "below".

Unlike in 3rd Edition, the Forgotten Realms cosmology and the generic setting cosmology are pretty much the same, the main difference being that FR has different domains within the Astral Sea due to the different deities in the setting.

AFAIK it hasn't entirely been made clear whether Toril is now a world in the Astral Sea, or if the Prime Material Plane and the Astral Sea are still separate. Spelljammer doesn't "officially" exist in 4th Edition (yet?), though many Spelljammer elements have been incorporated into the Astral Sea.