Diablo 3 Barbarian
If you played Diablo 2 then you should be fairly familiar with the Barbarian. The archetype is similar to that of the warrior / solider class found in many other RPGs. We’re talking about a two hand or dual wielding melee power house.

Diablo 3 Barbarian Skills and Abilities
Cleave – The barbarian deals large amounts of damage in a frontal cone (aprx. 150 degrees).
Ground Stomp – The barbarian stomps the crowd dealing damage and dazing enemies in a 360 degree range around the barbarian.
Leap – Similar to the leap from Diablo 2, the barbarian launches himself into the air aimed at a point of impact. At the chosen point enemies are damaged and knocked back in a 360 degree range around the Barbarian.
Seismic Slam – The barbarian slams the ground, sending a shockwave in a line directly in front of the Barbarian, dealing damage and killing enemies.
Whirlwind - The barbarian spins continuously dealing damage in a 360 degree range, you may move while spinning.

Diablo 3 Witch Doctor
The witch doctor is very similar to the necromancer from Diablo 2. The doctor has powerful debuffs, damage casted spells, and the ability to raise the dead to fight by their side.

Diablo 3 Witch Doctor Spells and Abilities
Firebomb - The witch doctor launches a fire bomb at a group of enemies, dealing heavy fire damage, knocking them back, and setting the ground on fire.
Horrify - The witch doctor sends enemies running with a horrifying scream.
Locust Swarm – The witch doctor launches a locust at a nearby enemy. After hitting an initial monster the locust will spread to nearby enemies, creating a swarm of devastation.
Mass Confusion - The witch doctor afflicts a large group of monsters with a confusing hex. The hex causes the monsters to swing wildly and wander around confused, allowing the witch doctor and party members to kill with easy or simply walk past the monsters.
Soul Harvest - The witch doctor creates a pulse of energy, killing nearby enemies and harvesting their souls. While nothing has been confirmed yet, it’s presumed that these harvested souls will be used in future unreleased spells.