Upcoming Mage changes
You can also check the upcoming Death Knight changes below, news have been split to make the discussion easier.

You already got reduced cost to most of your spells.
Blizzard does it in baby steps :>

These are interesting changes which make a lot of sense.  Not too much here that's surprising actually, considering they dropped a lot of hints.

I think the biggest surprise here is there is no corresponding nerf to Arcane Barrage.  I suppose this is because they expect Arcane's burst to be greatly diminished when PvP gear starts to scale survivability much higher, but still, the ability to cast AB one to three times on a Slowed target then rock them with a +15-45% damage Arcane Barrage and follow it up with a PoM pyro...could be a bit OP *grin*.  The side effect is of course opening up the mage to being locked out on his key Arcane defenses (mana shield, CS, blink, invis).    This is an important point because a (large) part of the OPness of Arcane spec in PvP was the high mobility this spec allowed while not opening itself up to lockout minus a 2.5s missile barrage of doom.

This really makes me want to try out Arcane again for PvE (I stayed Arcane from 3.0.2 in TBC until level 75).  Its a really fun spec and requires a lot more skill (now) to maximize the potential PvE damage than FFB or Frost does.  

This also fixes the Arcane haste scaling problems (arcane was haste soft-capped at 33%), though not the crit ones.  Not sure how much spirit is going to boost the damage of this spec though.  Its going to depend a lot on how desirable stacking an extra AB buff is going to be vs. releasing the lower damage ABar early to save mana.

Another important point: Precision change to nerf FFB (presuming the bugged extra 3% hit is gone with this change) + the change to Torment of the Weak brings Fire and Frost spec back into the mix of things for max PvE damage specs.  Looks like its going to be: Fire: More consistent damage, higher mana consumption; Frostfire, slightly lower or higher damage (depending on your crit%) and spikier damage, lower mana consumption.  Let the player decide the route.

In terms of overall damage, this is definitely a buff to the lesser used specs (Deep Arcane, Fire/Arc, and Frost/Arc).  It slightly nerfs Frostfire until mages regear accordingly.  (need 367 rather than 289 hit rating to cap out FFB)

Mage damage is a tad high at the higher gear levels according to parses I've seen but is largely dependent on the RNG.  I don't know if this justifies it as high, or if Warlocks and Rogues (non-bugged) are just low.  And please don't quote that 6500 dps mage parse...its rife with inconsistencies. 

I was expecting nerfs, not buffs to the mage class. They're pretty much in the same position as hunters were before nerf, heavily benefitting from short CDs and getting insane dps as the boss encounters take less and less time to finish, hence more time % of the fight under the influence of cooldown related selfbuffs.

edit: Although these were buffs to the Arcane, which isn't necessarily a bad thing, balance wise. But Blizzard should ask themselves the same things they did before nerfing hunters, towards mages.

Keep in mind that the proposed hunter nerfs still have yet to be tested on the PTR (along with these mage changes). Remember when the Pally nerfs were announced? Now look at the state of Pallies on live. What is announced and what will be implemented after testing are completely different.

Competitive FFB rotations are not single button fights, far from it:

LB
Scorch until cap
FFB
LB when out
Pyro on HS proc
FFB
Scorch to keep debuff up

May not be the most exquisite rotation ever, but far from single buttton macroed rotation...

Not too horrified by the changes. It makes me want to go deep arcane again if not for funzies. I like the cooldown reduction on evo, second one I believe since the expac dropped. Makes me not so fearful to go deep fire and blow my mana  Cheers.

True, but consider the changes overall.  Torment the weak now effects Arcane Blast, combine a cone of cold or improved blizzard to slow a mob and pop Arcane Potency with several Arcane Blasts while you have mana shield up.  Encanters absorption buffs your AE damage with each hit on it while torment the weak and AP buff it even more.  You can burn down mobs fairly quickly enmasse then pop Ice Block to drop aggro or Mirror Image and/or instant invisibility to pull your butt out of the massive aggro you just pulled.  Granted, you'll be depleted at the end but you have the luxury of determining whether or not you'll get back into the fight, evocate, or stand around waiting for the group to come back and pick up their bodies.  You know...  Like F'ing Hunters do now.

The instant invisibility thing is the best buff for mages EVER.  Get your butt in crap so deep they gotta drill for oil to find you then pop it and "Get Out of Dying Free" card every two minutes.  WOOT!