Seeing that there are repeated questions as to how the Arcane Decision Table is to be read, might I add adjustments to make it easier to see/imagine how the table is played for those who know what the numbers mean?
Could you consistently call 0 = Arcane Blast, 1 = Arcane Missiles, 2 = Arcane Barrage (or if that doesn't work due to triggers for AM, use 0 = ABla, 1 = ABar, 2 = AM)? That makes reading the table easier when I don't have to look whether 1 is AM or ABar in the current column. Also, could you add spaces after every 5 entries? "00010 00010 010" is much easier to trace than "0001000010010" when looking up when AM (or is it ABar in that column?) is to be cast. Starting with row 1 may also be more familiar than row 0, but I'm not a good person to judge that.

While I agree the 2pc T11 PVE bonus is horrible, I do not think the PVP bonuses are worth the worthless resilience. I'm giving rough estimate numbers here, but you'd be giving up about 730 points in secondary stats for the resilience (for 359 tier gear...more for 372. Compare that to 160 int. I think the 4pcT11 PVE bonus of 10% reduced AB cast time would also be more valuable than the 5% damage increase, although they might be closer than they appear. In theory, 10% reduced cast time should be 10% increased damage, however, with the mage dynamics, this would not be the case. This reduced cast time compared to a static mp5 (would be the same for either scenario) would lead to shorter burn phase and also potentially having to do ABx3 AM instead of ABx4 AM sometimes (presumably 10% of the time) during the conserve phase.

I usually rely on RAWR to calculate these exact numbers. I'm suprised with the results you're getting though. I would think the PVE stats/bonus would outweigh the PVP.

Now PVP vs. 346 blues, then go with the PVP!

OK, so this question is going to be laughed at, but there hasn't been much discussion on here recently, so I thought I'd throw it out:

How long are people typically holding on to their 4pT10 (264's) bonus? I know the saying goes cata greens are better than any wotlk gear, but I dont think this is the case for arcane. I tried on dummies using my 4pcT10 gear and then equipping about an average of blue 325 gear instead, and I was doing more damage with the 4pcT10. That 18% mirror image buff during the burn phase is just HUGE. Part of this too is I use an on use sp trinket, so that magnifies the burn phase even more.

I'm assuming in heroics and especially in raids this will definitely go away as you'll need all the extra stats for extra hit, but is there anyone else out there finding their dps is much better for the level 85 regular instances still using the 4pT10??? Or am I the only one this dumb lol.

It will depend a lot on what other gear you acquired while leveling. I haven't found 4T10 particularly strong, but I used 2T10 about one week into raiding until I got better pieces. Kind of related to the previous question, I also used 2 piece PVP set for quite some time. If you have the Vicious pieces those are item level 365 and the higher item level more than makes up for resilience until you have 4T11. In the end it all depends on what you have available, I would use whatever is best in your case, regardless of if it looks strange.

It seems to me that a lot of people are misunderstanding the mastery for Arcane. If you look closer at the wording of the mastery you will see that it is based upon unspent mana. Based on the wording it appears to be based on the actual amount actual mana unspent and not the percentage of unspent mana.

Can anyone confirm if this is correct?

I don't think that makes much of a difference, as the mastery bonus gives a set percentage increase in damage. If you had 100k mana or 200k mana, you're still getting the same percentage of extra damage.

You forgot to take the Int modifier into account:
Lets take a closer look to the Mana aspect of the Trinket (Procc * 1.1025x modifier= 1764 int ):

E1: Lets say you have 100k Mana, 22% Damage Bonus due to Mastery
((100.000/126460) * 0,22) +1 =1.174

E2: With 50k Mana, same Mastery
((50.000/76.460)*0.22)+1 =1.144

E3: With 500k Mana, same Mastery (for Finamenon)
((500.000/526.460)*0.22)+1 =1.209

So we can conclude that as your max Mana nears infinity, the damage loss due to Mana loss in % nears 0. The realistic damage bonus is between 1.144-1.15 %.

I am not sure about your damage calculations though:
+1600 Int (Intellect has a 1.1025x modifier) =>1764 Int
*1.174% increased damage after the loss in intellect as in example 1
*(0.02*Procc Mana) (Improved Mana Gem)=529.2

With Procc + Mana Gem:
1.3*1.174*((Procc_SP + 0.02*26460) *0.97)=3394.89 increased damage on AB

Can anyone tell me why they buffed everything by 13% ? It seems to be a very big buff, especially if we consider how long it took them to realize Arcane needs a change(and not by making ab even cheaper).

If these changes go live we do more damage, but it is still only ab spam as much as possible which is kinda dull in the long run

But it is nice that we can use blizzard now as an aoe. AE still sucks without the AB Buff and will be very situational.

I have updated the OP with a section on the Arcane specific PTR changes and I will continue to update that section as more changes occur. Given that the PTR is typically a fluid environment, I thought it would help us if a list of changes was in one place. The flat 13% increase in damage does not really affect any of the rotations or the phases, but the changes to AE might bring the Improved Arcane Explosion talent more into focus.

I have not yet run any tests, but wouldn't we need to see something more added to arcane explosion to make it a viable aoe. I was thinking of having it refresh the AB blast stacks when you cast arcane explosion. Do they really expect us to cast an AB to keep our stacks up while AOE'n. Seems as though it would really hinder our AOE if we have to do so. You could use POM to refresh it once, but after that you have to stop and cast AB. Maybe I'm wrong tho, has anyone done any tests? Would it be to strong to have it work in such a manner?

The mage changes are not on the PTR yet (just in the notes) so there is currently no way to test it.