Spooncraft

Mages wield the elements of fire, frost, and the arcane to destroy or neutralize their enemies. They are a robed class that excels at dealing massive damage from afar, casting elemental bolts at a single target, or raining destruction down upon their enemies in a wide area of effect. Mages can also augment their allies’ spell-casting powers, summon food or drink to restore their friends, and even travel across the world in an instant by opening arcane portals to distant lands.

Arcane: Arcane mages have been given some mighty powerful tools in Wrath of the Lich King. To break it down somewhat into simple terms, Arcance mages have really great burst damage and strong utility spells like Slow, but they sacrifice some control and added damage in favor of mobility. Almost all of their main arcane spells are either instant cast or can be augmented to nearly instant.3

Fire: Fire mages have always been the killers of mage DPS. They have really strong area of effect spells like flamestrike and blastwave, and the new living bomb spell that can break down large groups of enemies rather quickly. Fire magi spells almost always leave a lasting damage over time effect as the burns leave their mark on a singed target. They have the most damage but again, not much control and not as much mobility as an arcane mage.

Frost: Frost is all about control. Through shatter combos a frost mage can have some very impressive burst damage but it’s situational and conditional in contrast to the arcane mage. Frost also lacks the raw power of a fire spec mage, however. Frost mages have the most control of all three specs. They can root multiple targets in place at a distance allowing them to pour frost damage without respite. Their frostbolts and ice lance spells maximize their damage when a target gets frostbitten, they can locckdown their enemies in blocks of ice and stun them from a distance as well. They make great PVP mages since they also have more armor spells that slow down or freeze attackers if the damage ins’t completel absorbed.

Wowhead has a really great talent calculator where you can experiment with new builds for your Mage.