I think the answer to ae or blizzard is: It depends!
Given trash packs, maybe with random agro or a melee aoe, as they exist in ICC, the obvious choise is Blizzard.
When allready standing in melee range or being "on the move" ae got it´s place, it s slightly higher dps and usually more mana efficient then blizzard aswell.

I would like to discuss talent choises for the current ICC content.
I tried droping range but did really miss it, f.e. in the Gunship battle I had to move a bit to hit Axethrowers on other side.
IA seems also be really worth it especially together with me using frost and fireward pretty often to procing magic absorption.

But with 2 points and magic absorption and 2 points in IA there are just no points left to spend apart droping some of the "classical" dps point choises.

Tommynt, you might want to consider using an FFB spec for Gunship. If you're like myself, you already have an FFB spec ready for use on heroic Anub, so it's an easy switch. I've seen some pretty good results thus far, and given the number of mobs and AoE going on in that fight, I can't think of a reason not to just spam LBs and Blizzard all day long. Blizzarding the portal spawns as Arcane could prove problematic with threat anyway.

Regarding Arcane Stability: The only justification I can offer is the pushback caused by Lord Marrowgar's Bone Storm. It doesn't last long, and you might spend more time running around than finding opportunities to stand still and cast, although the damage is pretty insignificant anyway. Keep in mind, however, that in the heroic version of the encounter, Lord Marrowgar continues to cast Bone Spikes during his Bone Storm phases, making those few points in Arcane Stability much more valuable.

I'm assuming mages will be able to remove at least one point from Arcane Subtlety when tanks begin to acquire their 2pcT10 and switch the point/s over to Arcane Stability. I know its very early in the patch for many people to have T10, but has anyone experienced aggro control with tanks that have their additional 20% increased damage abilities?

How would Pushback Protection be valuable against Bone Spike Graveyard. From what I have read about the ability (and seen on various videos) is that when a spike hits a player, he/she is impaled and stunned until the spike is destroyed. If the spell does stun, then the current spell cast will be immediately interrupted, not pushed-back, making pushback useless.

EDIT: Sorry for the misinterpretation, thought Arbitur was referring to Bone spike avoidance

Pushback protection would allow you to free someone faster while taking hits from Bone Storm.

I believe tommynt meant "procing Incanter's Absorption" instead of "Magic Absorption" there, given the context of the rest of his post.

I would also like to point out that even if using Arcane Explosion to AoE, so long as the mobs aren't being moved around too much as mentioned, it is still a dps increase to Flamestrike every 8 seconds in between Arcane Explosions.

Well, yes and no.
Wards to negate perodic or multiple hitting damage will proc both Incanter´s Absorption and Frost Warding giving both Mana and additional spell damage. I got used to ward myself allways when being on the move as there is in nearly every encounter some sort of fire or frost damage with quite a high chance to hit you.
When being not 100% certain if it s better then the Barrage u could do I feel way more save this way - better to gain spelldamage and mana than dieing to bitting cold.

I am not sure how much magic Absorbtion helps, thats why I asked for a discussion on these optional talents.

In what way, are you referring to the switch between mashing a single button to having to place a FS ring, or do you mean because you can't que FS server-side while on the AE GCD? I do it all the time and don't find it too complex, well not enough to warrant sacrificing our best damage-per-cast time AoE. If you have difficulty timing 8 seconds there are mods you can use to track when to recast FS.

It's not tracking the DOT, it's alternating between spamming Arcane Explosion and placing a Flamestrike circle down. It's a very unintuitive switch to make. It's different for everyone of course, and maybe something that can be mastered, but for a lot of players I'd imagine landing a Flametrike inbetween AE will actually hinder them rather than help them in many cases.

Actually the range is only 10 yards (the tooltip listed value) when moving - it is around 1.4 yard lower when standing still.

Apart from that there is one significant difference between AE and Blizzard and that is what happens when it isn't a tank and spank aoe fight, but rather ping pong aoe with mobs changing target all the time due to people over aggroing, tank being bad on threat, tank moving mobs for whatever reason or new mobs spawning from multiple directions. In those situations I usually find AE spam to be a better choice. Especially in random heroics with poor tanks and mobs who doesn't hit for anything anyway just running around the tank spamming AE is both safer and more damage than pulling them away from the tank with blizzard. On ICC trash and generally on exploding/cleaving trash I would never go AE though.

There is no such thing as an 'optimal rotation' that works for every fight. Kavan's tables show the dps/mps trade-off between different rotations and it's up to you to choose what to do depending on the fight. Indeed pure AB spam will be less dps than using up your missile barrage procs, but you do still want to spam AB to get the proc in the first place.

In regards to using MBarr at 2 or 3 stacks, yes of course it can be beneficial. Looking at Kavan's numbers, it suggests that you would effectively exchange a little over 1% dps for a 35% mana saving. Once you have 2T10 you can start experimenting on which fights you'll need to do this.