You are unlikely to see a huge DPS boost when going to arcane. It's similar DPS to fire (within 5%) on tank and spank fights now. Fire is stronger on any fight with 2+ targets for a portion of the time, and is probably stronger on mobility fights as well.
For fire/frostfire, it's definitely worth getting Combustion now. Just drop a point in Student of the mind or World in Flames.
If you do go arcane, however, it's a simple rotation now:
Spam AB until you get a missile barrage proc. Make sure you have a full 4 stacks of AB. Then cast a Missile Barrage Arcane Missiles.
So if you get the MB proc on the first AB, you still keep casting AB until you get to 4. If you don't have one at 4, you keep casting until you do. It seems likely this is sustainable, although only actual raiding will tell.
Spec for Arcane Barrage but don't use it unless you're moving.
>>>>>>> READ MORE AND COMMENTS >>>>>>>>