For those who haven't seen, the relevant changes for arcane were:
Mage
* Arcane Missiles' damage is increased by 50% per Arcane Charge (up from 25%).
Talents
* Scorch now costs 2% of Base Mana (down from 3.5%).
Arcane
* Arcane Barrage's damage is increased by 50% per Arcane Charge (up from 25%), and it hits 1 additional nearby targets per Arcane Charge for 50% damage.
* Arcane Blast's damage is increased by 50% per Arcane Charge (up from 25%), and its mana cost is increased by 150% per Arcane Charge (up from 75%).
* [...] Scorch's damage is increased by 50% per Arcane Charge, and its mana cost increased by 150% per Arcane Charge. Stacks up to 4 times (down from 6) and lasts 10 sec.
* Arcane Missiles' damage is increased by 50% per Arcane Charge (up from 25%).
So these changes mean a few things:
- Scorch-weaving is obviously out, but other specs can use it at a relatively low cost (not free, however).
- Arcane's ramp-up is going to be a lot faster (roughly 33% faster).
- Overall damage should INCREASE for those who can manage their mana properly, as the damage of each ability is now increased by 200% at max stacks instead of 150%.
- Overall damage should DECREASE for those who cannot manage their mana properly, as the mana cost of Arcane Blast (and Scorch) is now increased by 600% at max stacks instead of 450%.
- The new common rotation will probably return to what it was before Scorch-weaving, which was:
- Cast Arcane Blast to max stacks, use Arcane Missiles whenever two charges are available.
- At maximum stacks, use all available Arcane Missiles charges.
- If above 90% mana, use Arcane Blast until at 80-85% mana.
- If cooldowns are available (Arcane Power, Mana Gem, Alter Time Potions, Trinkets, Etc...) use them, try to match up this phase with Heroism.
- While cooldowns are active, use Arcane Blast to get Arcane Missiles charges, and then use them.
- If you have Evocation, continue until at approximately 30% mana and then use it. If you do not have Evocation, continue until approximately 60-70% mana.
- Use Arcane Barrage to reset stacks of Arcane Charge, then restart rotation.
- Arcane Explosion might be used to generate Arcane Missiles charges at max stacks, especially in multi-target fights, as Arcane Explosion will cost 3% base mana and Scorch will cost 12% base mana.