Arcane Focus
Talent · ArcaneChangedOpen in the talent calculator
Arcane FocusRank 5/5
Reduces the chance that the opponent can resist your Arcane spells by 10%.
Arcane FocusRank 5/5
Improves your chance to hit with Arcane spells by 5%.
News
Classic vs Forever
Every talent and spell WoW Forever added, changed or removed, with the Classic tooltip next to the new one.
Mage changes
Arcane
Wand SpecializationRow 2to 1MovedTalent · Arcane
Arcane FocusMax rank 10%to 5%ChangedTalent · ArcaneClassic Forever 
Improved ChannelingWas Improved Arcane MissilesChangedTalent · Arcane
Arcane SubtletyMax rank 10to 15;40%to 30%; Row1to 2ChangedTalent · Arcane
Magic AbsorptionMax rank 5%to 2%; Ranks5to 2ChangedTalent · Arcane
Arcane ResilienceRow 3to 2; Ranks1to 2ChangedTalent · Arcane
Arcane GeometryWas Magic AttunementChangedTalent · Arcane
Arcane ImpactWas Improved Arcane ExplosionChangedTalent · Arcane
Arcane BlastBlasts the target with energy, dealing 57 to 65 Arcane damage. Each time you cast Arcane Blast, the damage of all your…NewTalent · Arcane
Arcane ShieldingWas Improved Mana ShieldChangedTalent · Arcane
Improved CounterspellRank 1 4 secto 2 secChangedTalent · Arcane
Arcane MeditationMax rank 15%to 50%; Column4to 3; Now needs Arcane ConcentrationChangedTalent · Arcane
Missile BarrageGives your Arcane Blast spell a 40% chance, and your Fireball, Frostbolt, and Frostfire Bolt spells a 20% chance to…NewTalent · Arcane
Arcane MindNo longer needs Arcane ResilienceChangedTalent · Arcane
Arcane InstabilityColumn 2to 3; No longer needs Presence of MindChangedTalent · Arcane
Arcane PowerNeeds Presence of MindChangedTalent · Arcane
Teleport: DalaranTeleports the caster to Dalaran.NewSpell · Arcane
Arcane IntellectIncreases the target's Intellect by 31 for 1 hr.ChangedSpell · Arcane
Conjure FoodRank 6 18to 20ChangedSpell · Arcane- Arcane MissilesMax rank
230to 209ChangedSpell · Arcane 
Dampen MagicMax rank 90to 135;180to 270ChangedSpell · Arcane- Arcane ExplosionMax rank
249 to 270to 239 to 258ChangedSpell · Arcane 
Amplify MagicMax rank 75to 113;150to 225ChangedSpell · Arcane
Remove Lesser CurseRemoves 1 Curse or Bane from a friendly target.ChangedSpell · Arcane
BlinkTeleports the caster 20 yards forward, unless something is in the way. Also frees the caster from Stuns and Immobilizes.ChangedSpell · Arcane
Mage ArmorMax rank 30%to 50%ChangedSpell · Arcane
Arcane BrillianceInfuses the target's party and raid with brilliance, increasing their Intellect by 31 for 1 hr.ChangedSpell · Arcane
Fire
Wake of FireWas Improved Fire Blast; Max rank 1.5 secto 2 sec; Row2to 1; Ranks3to 2ChangedTalent · Fire
IncinerationWas Incinerate; Max rank 4%to 6%; Row3to 1; Ranks2to 3ChangedTalent · Fire
Improved FireballColumn 2to 3ChangedTalent · Fire
ImpactRow 1to 2; Ranks5to 3ChangedTalent · Fire
Burning SoulColumn 4to 1; Ranks2to 3ChangedTalent · Fire
Pyroblast148 to 195to 101 to 131;56to 44ChangedTalent · Fire
Improved ScorchRank 2 66%to 67%ChangedTalent · Fire
Heating UpNon-periodic critical strikes with Fireball, Frostfire Bolt, Fire Blast, and Scorch reduce the cast time of your next…NewTalent · Fire
Master of ElementsYour Fire and Frost critical strikes will refund 30% of their base mana cost.ChangedTalent · Fire
Blast Wave160 to 192to 154 to 184; No longer needs PyroblastChangedTalent · Fire
CombustionWhen activated, this spell causes each of your Fire damage spell hits to increase your critical strike chance with Fire…ChangedTalent · Fire
Frostfire BoltLaunches a bolt of frostfire at the enemy, causing 270 to 314 Frostfire damage, slowing movement speed by 40% and…NewSpell · Fire- FireballMax rank
596 to 760to 425 to 541;76to 60ChangedSpell · Fire 
Fire BlastMax rank 446 to 524to 417 to 489ChangedSpell · Fire
FlamestrikeMax rank 381to 382;340to 332ChangedSpell · Fire
Fire WardMax rank 920to 913ChangedSpell · Fire
ScorchMax rank 237 to 280to 167 to 196ChangedSpell · Fire
Frost
Frost WardingIncreases the Armor and resistance given by your Frost Armor and Ice Armor spells by 30%. In addition, gives your Frost…ChangedTalent · Frost
Elemental PrecisionMax rank 6%to 5%; Ranks3to 5ChangedTalent · Frost
PermafrostRank 1 4%to 3%; Column4to 2ChangedTalent · Frost
FrostbiteColumn 2to 4MovedTalent · Frost
Frost ChannelingRow 4to 3MovedTalent · Frost
Ice LanceDeals 28 to 32 Frost damage to an enemy target. Deals 300% increased damage to Frozen targets.NewTalent · Frost
Improved BlizzardAdds a Chill effect to your Blizzard spell. This effect lowers the target's movement speed by 40% for 1.5 sec.ChangedTalent · Frost
Ice BlockRow 5to 4MovedTalent · Frost
ShatterColumn 3to 4; No longer needs Improved Frost Nova; Ranks5to 3ChangedTalent · Frost
Improved Cone of ColdRank 2 25%to 23%; Column3to 1ChangedTalent · Frost
Cold SnapRow 3to 5ChangedTalent · Frost
Fingers of FrostGives your Chill effects a 15% chance to grant you the Fingers of Frost effect, which treats your next 2 spells cast as…NewTalent · Frost
Winter's ChillRank 4 5to 4ChangedTalent · Frost
Ice Barrier455 damageto 448 damage; Needs Cold SnapChangedTalent · Frost
FrostboltMax rank 515 to 555to 457 to 493ChangedSpell · Frost
Frost NovaMax rank 73 to 82to 72 to 79ChangedSpell · Frost- BlizzardMax rank
1192to 1168ChangedSpell · Frost - Frost WardMax rank
920to 913ChangedSpell · Frost - Cone of ColdMax rank
338 to 368to 328 to 358;50%to 40%ChangedSpell · Frost
Comprehension
What changed during the beta, update by update, is in the patch notes. To try a build, use the talent calculator.