Mage

Arcane Barrage mana cost has been reduced by 8%.
Arcane Blast mana cost has been reduced by 12%.
The mana costs of Arcane Brilliance and Dalaran Brilliance have been reduced by approximately 16%, making them roughly equal to the cost of Mark of the Wild.
Counterspell lockout duration reduced to 7 seconds, down from 8.
Fireball mana cost has been reduced to 9% of base mana.
Flame Orb now ignores critters.
Frostfire Bolt mana cost has been reduced to 9% of base mana.
Mage Armor now reduces the duration of magic effects by 35%, down from 50%.
Molten Armor, Mage Armor, and Frost Armor no longer cost mana.
Polymorph now has a PvP duration of 8 seconds.
Ring of Frost: Radius shrunk to 8 yards, and inner “safe” radius is now 4.7 yards (exactly matching graphic). Dispelling the effect of Ring of Frost will now make the target immune to being refrozen for 3 seconds. If a second Ring of Frost is cast by the same mage while the first is still active (via Cold Snap), the first will now disappear and cease functioning. In addition, Ring of Frost now has a PvP duration of 8 seconds.
When a mage uses the Invisibility spell, it will now also cause their pet Water Elemental to become invisible.

Talent Specializations

Arcane

Slow now has a PvP duration of 8 seconds.

Fire

Firestarter now allows the mage to cast Scorch while moving (regardless of which armor spell is used), and no longer eliminates Molten Armor’s critical strike chance reduction.
Flashburn (Mastery) benefit per mastery has been increased by 12%.
Living Bomb mana cost has been reduced by 22%.

Frost

Deep Freeze damage done has been reduced by 20%.
Fingers of Frost can no longer be dispelled and now also increases Ice Lance damage by 15%.
Frost Specialization now only grants 2 base points of mastery (instead of 8), reducing all Frost damage to frozen targets by 15% from previous values. However, Frost Specialization now increases base Frostbolt damage by 15%.

Mage Bug Fixes

Arcane Power now has its tooltip updated when Glyph of Arcane Power is active.
The attachment point of Cone of Cold was too far left and has been adjusted on male troll models.
Evocation was returning less mana than the tooltip stated it should. This has been corrected.
Flame Orb’s tooltip should now state how much damage it will explode for after the Fire Power talent is chosen.
Rank 1 Frostfire Orb is no longer applying a debuff that incorrectly states that it snares its target.
Molten Armor tooltips now display the correct information.
Nether Vortex was causing Arcane Blast to yield a string error when Arcane Blast was reflected. It shouldn’t do that.
When Presence of Mind was active, Conjure Mana Gem was not becoming an instant cast spell if used to refresh a stack of 2 or less Mana Gems. This has been fixed.
Presence of Mind is no longer consumed when Flame Orb is cast.
Ring of Frost can now be cast and works properly on transports (this includes elevators, trapdoors, etc.).

Glyph Fixes

Glyph of Arcane Power should correctly reduce the global cooldown of Blink, Mana Shield, and Mirror Image to 0.
Ice Barrier’s tooltip is now correctly updated by Glyph of Ice Barrier.