Though there are many nice things in the forthcoming patch 3.1, there are also a few major changes that my mage will NOT be looking forward to.
Nerfing Molten Armor
Mages have been complaining that spirit is a useless stat for us for a while now. Blizzard wants to put it on gear because the other clothies all benefit from it, and spending item budget on it slows the growth rate of caster DPS. The catch is that mages currently get no DPS benefit from spirit, and, by design, get only minimal benefit from spirit for mana regen.
To keep from pigeon-holing mages into the increasingly small minority of caster gear that does not have spirit (such as all of the gear that I'm currently wearing), Blizzard is gutting the molten armor spell, and allowing mages to make up the difference with spirit. The spell currently offers 3% crit - 5% with the glyph - and will now offer 25% of your spirit - or 40% with the glyph - in critical strike RATING. It takes 46 rating to get 1% crit, so it would take 575 spirit for a mage with the glyph to get back to the 5% mages currently have.
The catch is that I don't raid, so I won't have access to Ulduar gear (which offers spirit in addition to, rather than instead of, my current DPS stats). I also cannot count on the various spirit buffs that help members of 25-man raid groups approach that 575 spirit number. As a result, in most settings, I will lose 3% crit from these changes.
Farewell to Impact
Impact is also being changed from its current form, a 10% of a stun on all forms of mage damage (including Blizzard and Molten Armor, which can be talented to work at range), to a new stun tied to fire blast. This change was probably needed for PVP, and at least this time I'm the target of the nerf. Having a random stun on my main nuke, against every foe that hits me, and in the stunning, chilling, freezing, crit spamming storm of death that is Blizzard with all the utility talents has been a lot of fun.
Other than in solo play, I will miss the effect most on caster trash mobs in instances. Like mages, caster mobs who are randomly stunned lose their spellcasts and have to restart their cast bar when the stun wears off. When you're rounding up instance trash for AOE, the stun from Blizzard actually interrupts a significant number of spellcasts. It also keeps the mob in the Blizzard area, where it is taking damage, has a chance to be frozen, and generally is not running over to kill the mage. Those of you mages who have not experienced this may want to give a Frost/Fire spec a try sometime before the patch (or you may not, if you don't WANT to know the fun you've missed) on some hapless heroic instance run. Bring a Pally tank. :)
Losing more damage to balancing
In addition to all of these changes, Blizzard is halving the effect of Winter's Chill (a buff I was able to supply) and Improved Scorch, due to concerns that crit rates are already high. Added to the Molten Armor change, I'm losing 8% crit on patch day. In addition to damage, I also rely on critical strikes for mana via Master of Elements. I'm not fond of sounding melodramatic, but I think that the spec I've had fun with for the past few months may be dead after these changes, collateral damage of balance changes that may (or may not) have been needed for other parts of the game.
The Frost/Fire talent combination is the worst of the six possible tree/off-tree combination for mages at the moment, in terms of raw DPS. In best-of-heroic 5-man gear, I am able to break the 2K DPS barrier that people draw when they want "good" DPS - the lost crit may knock me back down below that line. In exchange for this mediocre DPS, Frost/Fire mages get unparalleled utility - all of the talents that real frost specs get, an extra seven points to spend on utility talents (normally spent on talents that affect frostbolt but NOT frostfire bolt).
After the patch, I will offer less utility due to the loss of Impact and the nerf to Winter's Chill, less damage due to the crit nerf, and, as a final insult, I will not even be allowed to provide the group replenishment buff that real frost specs are getting, because that talent is specific to Frostbolt. (Real frostfire specs - the fire based ones that do competitive damage - cannot reach 43 points in frost, so I'm really unclear on why they feel so strongly that replenishment cannot include frostfire bolt.) Oh, and Water Elementals still do not have "standard pet AOE avoidance", which was granted to priests' Shadowfiends, meaning that 10-15% of my DPS depends on the RNG not deciding to drop an AOE on my helpless elemental.
Surveying the fallout
The crab comes into a lengthy Q&A thread from dissatisfied mages, and argues that the rebalancing to crit is alright because soloing is easy. Technically speaking, he may be correct. However, it is strange to see the low end of content - the solo and 5-man stuff I focus on - effectively written off as not mattering for balance because it's all easy anyway.
After the patch I'm going to go from having a relatively unusual but fun spec to having the same two specs that most other mages will carry - a frost/arcane replenishment spec (18 arc is mandatory thanks to Torment the Weak), and either a Fireball spec or an Arcane Barrage spec for actually doing damage. That loss of individuality is unfortunate in an era where all of the non-cosmetic distinctions between characters are already blurring.