Raiding specc is very obvious, this is what we will use at LVL 80 - http://wowtal.com/#k=lsnam3Wl.9zi.mage
And this is what well use when we get the other 5 points at 85 - http://wowtal.com/#k=ZwPWEUCPv.9zi.mage
The thing im not sure about is the changes to the rotation and obviously a lot of math by smarter people than myself will determine this so I figured there are a few interesting things we can talk about now.
1- Molten armor or Mage armor? I can see this depending on how many PI's and Innervates the raid plans on giving the arcane mage on every boss fight, but Mage armor is now giving back around 1k mana every 5 seconds to my mage, and with the new mastery giving 12% bonus damage if you keep your mana near full for the fight i can see MAYBE mage armor becoming used for Arc raiding mages?
2- Currently on live with the 30% ICC buff Its best to keep spamming Arcane blast until you get a missile procc even if that means going 12 blasts in a row, and you just generally call out for an innervate. BUT when ICC was new and I was working on heroic mode boss's before any ICC buff was released it was easier to go OOM, if you werent careful you could find yourself standing there wanding for 20 seconds waiting for Evoc to come off CD. So the answer then was to channel unprocc'd missiles at 4 stacks of blast because that was still better damage than clearing the 4 stack with a Barrage. So now with missiles unable to be cast without a procc you are unable to clear your 4 stack of blast with unprocced missiles. I noticed that the CD on barrage has been raised to 5 seconds up from 3 seconds and im guessing that is apart of there plan to raise the scaling damage of Barrage and not have it be OP in PVP, but so that raiders would now WANT to use it to clear Blast at 4 stacks if missiles did not procc.
3- You obviously cannot reach Icy Veins any more as an Arcane raid mage which leaves you with only Arcane Power to POP for damage CD's and this may lead alot to believe that Arcane is nerfed, but the difference so far for me is that instead of my deeps going to 15k self buffed on the dummy when I pop Mirrors, Power, Icy Veins, and then dropping to hover around 7k after my CD's are gone. On the PTR im holding a much more steady 9k self buffed. And thats with using Molten armor like on live, but clearing my blast stacks at 4 each time with either a Barrage or a Missile if procc'd. I have yet to test If spamming Blast Until Missiles procc and completely skipping the use of Barrage like you would on live and just letting the Mastery drop fast is worth it.