I will use this post (and keep it updated) to track a summation of the changes in 2.4 that will impact mages. If there is a specific change that I want to elaborate on, I'll link to the detailed post.

I've rated the following changes on a scale of -10 to +10. Zero is neutral or negligible impact. Minus points are for nerfs, positives for buffs. The higher the number, the greater the impact.

• (+4) Gear - Crafted and Heroic Badges
• (+7) Spirit-based Mana Regen - retooled so that as INT rises, you regen more mana per SPI point
• (+7) Spell Haste reduces Global Cooldown to 1 second
• (-2) Drinking - ramp-up to Mana Restoration
• (+3) Arcane Explosion: The damage cap for area of effect damage on this spell has been increased by approximately 50%.
• (+1) Arcane Fortitude now increases your armor by an amount equal to 100% of your Intellect, up from 50%.
• (+1) Blink, Slow, and Spellsteal have all had their mana cost reduced.
• (-1) Using low ranks of Fire Ward and Frost Ward spell will now be penalized the same way healing spells are penalized.
• (-2) Frostbite: When a frost spell is reflected back at a Mage, it is now possible for the Mage to suffer from the Frostbite effect.
• (-1) Ice Barrier: Using low ranks of this spell will now be penalized the same way healing spells are penalized.
• (-4) Icy Veins no longer stacks with Bloodlust/Heroism. UPDATE: This has now been removed from the Patch Notes. IV now stacks with B/H, but will no longer stack with Arcane Power.  The score has been changed to reflect the update.
• (+3) Improved FireWard has become Molten Shields.
• (+3) New Talent: Molten Shields will cause your Fire Ward to have a 10/20% chance to reflect Fire spells while active. In addition, your Molten Armor has a 50/100% chance to affect ranged and spell attacks.
• (-3) Permafrost: This talent will now correctly increase the movement slowing effect of frost Armor instead of the attack speed slow.
• (+1) Spellsteal will no longer overwrite a longer duration buff.
• (+6) Icy Veins causes spells to be uninterruptible during IV duration.
• (+4) Imp Blink mana cost is reduced and adds a buff that reduces melee dmg by 25%.

The three worth discussing are the Mana Regen, the Spell Haste, and the IV+H/BL nerf.

I've started thinking about Mana Regen as regarding Arcane spec in this message.

I'll post about the other two when I collect my thoughts.