Battle-mages are fierce combatants, masters of the sword and spell. While in combat, they are not afraid to fight along with ordinary soldiers on the frontlines, decimating their foes in a quick whrillwind of attacks. Battle-Mages specialise in quick spell rituals called battlemagics wich are more suited for combat but lack the grace of a real mage's spells. Unlike mages, they wear plate armor, and they have forsaken the more civil use of spellcasting, namely conjuring food and opening portals, so they can focus on their skills with the sword (and sometimes, shield)
Weapons: All Battle-Mages are versed in using 1-handed weapons and carry an off-hand item in their free hand. Spellwarriors can equip 2-handed swords, axes, and polearms. Spellbreakers can equip a shield in their offhand.
Armor: battle-mages use plate. Spellbreakers use Int. Plate and weapons/shields, while Spellwarriors use Strenght plate
Resource Concentration (basically a mix of rage and mana, purple colour) melee attacks gain you concentration, spells dump it. Regenerates to 100% while not in battle, but while in battle the only way to recharge is attacking with your melee attacks (and some spells too).
Races Various. I'm only sure about Blood elves and Humans. Alltough Forsaken and Draenei are good options aswell. Gnomes I just cant see being spellbreakers at all.
Spellwarrior [Melee DPS]
Spellwarriors are masters of the sword, using spells only to merely support themselves. Most of their concentration goes on maintaining various auras they surround themselves with [Damage reduction shield, Flame aura that does AoE], while they focus on charging up their concentration with melee attacks. If their concentration vanishes, their aura does so aswell. If their concentration is great, they can "Overcharge" that aura for an additional effect. (Flame aura does an explosion around the spellwarior, doing a lot of AoE damage). Playstyle-wise, you battle to gain as much concentration as you can so you can buff up your damage output (or defensive capability). They can use 2-handed weapons and benefit from Strenght and Stamina.
Melee wise their attacks have various effects, but are mainly debuffing. Their auto attacks don't gain them concentration, but all their melee skills do. Some of theese skills lower the enemy's resistance to magic, so they take more damage when you overcharge your aura, some reduce stats, and some just hurt a lot.
PvP wise Spellwarriors are really tough opponents, if you let them chain melee attacks on you. So keep them away and everything should be fine. Just be aware, they have spells to catch up with you, and when you stun or incapacitate them, they gain concentration.
Time-walkers are not exactly healers. They make it so that the damage was never done in the first place. They do not directly heal anyone, they just make it so that while fighting their enemies, the enemies' attacks never happen, or do less damage. Exclusive to a time-walker is that even if he is not in melee range attacking, his concentration still recharges, alltough at a slower rate. In adittion to their attacks, they can place a time-zone around themselves wich slows enemies and makes friends faster. A time-walker is not versed in melee-fighting as a Spellwarrior, but he compensates for that by making the target he attacks do less damage or no damage at all to whoever the enemy attacks (the tank, mainly).
They are not able to go back or forwards in time, their craft lies in spells that only changes the time by seconds and sometimes even less, just about enough to be able to dodge an attack.
Spellbreakers are the Battle-Mage tanks. While they have innate resistance to magic attacks, they carry a big shield wich defends them from the physical aspect of harm. Theese battle-mages can exclusively equip shields. Their playstyle is very reactive to the enviroment they are surrounded by (or, the enemies they are surrounded by) While they are not the toughest of tanks to begin with, they spend their concentration on placing wards on themselves, guarding them from diffrent kinds of damage, becoming more tougher than anyone. While they use their melee attacks to gain concentration and debuff their enemies' attack power, they can spend it on spells that makes them even tougher , taunting, interrupting spellcasting, countering enemy spells (cause that is what a spellbreaker should do) and downright stealing their buffs for his own use (only temporary tough) and generally doing tanky stuff. All in all, a very tough motherF-er to kill.