Changes to talents:
Arcane:
Change arcane fortitude to Wisdom Eternal. +mana restoration (even while casting) equal to 10% of your total intelect.
Change wand specialisation into Mana Pyres. When you strike a critical hit, you gain full mana restoration for 6 seconds while casting. Also +1 crit%.
Give us another tier 1 talent. Spellfire: +1% to all spell damage.
Change magic attunement into Mind Wall. Gives you 5 seperate shields, one for every kind of magic. For example, Frost shield, Fire shield, Arcane shield, Nature shield, and shadow shield. If your frost shield broke, you'd take damage from frost, but the fire shield would remain active. Make it absorb ~400 damage at rank 1, ~600 at rank 2, 850 at rank 3, 1050 at rank 4, and ~1350 at rank 5 at level 70. Give every seperate shield a +bonus to damage absorbed according to your +spell damage in that school.
Change arcane impact to give the bonuses to ALL your arcane spells. Including missles. Also give it a -2% mana used per rank for arcane spells.
Change improved mana shield to Arcane Attunement. +2% arcane damage, -3% arcane spell mana use.
Change improved blink so it doesn't cut mana cost by 25%, but the cooldown.
Give PoM 3 ranks, where it's cooldown is 3 min at rank 1, 2 min at rank 2, and 1 min at rank 3.
Increase Arcane Mind bonus to 4% per rank.
Increase prismatic cloak to 10% per rank. With the extreme frailty of mages, -20% damage still wouldn't save them in raids, it would give them a bonus in PvP though. Which is good, since non-frost mages get murdered (Especially in arenas).
Increase arcane instability to 2% per rank, but remove rank 3.
Increase arcane potency by 25% per rank.
Remove +mana cost of empowered AM.
Make arcane power a stance you can turn on and off. May seem overpowered, but constantly casting with arcane power would leech you out of mana very, very fast. Of course, make it dispelable; If dispelled, it's cooldown would be 1 min.
Mind mastery and Spell power are fine as it is. Give slow -20% attack speed with melee attacks though.
Fire:
Change Improved flamestrike into Searing Mind. +20% critical strike damage bonus with fire spells. At max rank (3), you'd get +60%. Normally, if a fireball hits for 1000, crit hits for 1500, this would hit with 1500 + 60% of 500.
Give Improved fire ward a 50% chance to reflect at max rank.
Increase Playing With fire to 2%.
Blazing speed is fine, increase fire power to 3-4%. Fire should be the max damage, no survivability build.. So increase the damage.
Give pyromaniac a 2% for mana cost, but leave crit chance as it is.
Give combustion 4 charges.
Molten fury is fine, great for raids. Give it +2% fire damage without 20% health though, to give it a point outside of raids.
Change empowered fireball to Rolling Flames. Basically, it remains the same, but applies to pyroblast now as well.
Increase disorient of dragons breath to 4-5 secs.
Frost:
Same improvement to frost ward as with fire ward.
Increase frostbite 4 seconds.
Increase piercing ice to 4%. (Per rank)
Reduce cold snap cooldown to 3 minutes.
Also reduce ice block to 3 minutes.
Increase ice floes to 15% per rank, and make it apply to the elemental as well.
Other then that, it's fine.