1111111111111111111111111111111111111evocation1111111managemcooldowns111111111111112111121111112111112111112111111111211112112111112evocation1111111111getoutofthefire3111111111111111111111111111111111111111boss is dead.

roughly speaking.

EJ has an awesome Arcane guide and rotation breakdown, although Da Pants (akin to Da Bears, or also, Da Shorts) does a much better job of explaining WHY.

Arcane Blast until 40%ish, blow your mana CDs back to 100%, then AB + AM whenever it procs until your mana regens are off CD. Burn, refresh, conserve, burn.

And it works. I've been absolutely rocking the 5 mans I've been in with my crappy non-ICC gear. I landed a 37k crit earlier today (I think it was a Warlock, too). I'm still picking pieces of human out of my long elven trusses. I giggled inside, too.

Actually it's more like:
1. Do 3 ABs
2. Blow all the DPS cooldowns (AP, Gem, Trinkets, Mirror Images)
3. Spam AB until you are under 40% mana (burn phase)
4. Cast the missiles you have procced, a couple more ABs, missiles again (until your DPS buff run out)
5. Evocate to 100%
6. Do the 2-3AB + AM or ABar rotation to keep your mana over 90% until 10-15 seconds before your Evocation comes off the cooldown
7. Go to 2

With good gear, AB crits over 70k should be normal in the burn phase.