Why not ? It will definetly hype and spice up the mage game-play. I was, and am still, at the supporting side of the Blizzard’s
“support spec” experiment. They began with augmentation and yet still experiencing problems how to place it i know. but for me, warcraft is a world of “fantasies” and players options for their “path” must be as wide as possible !
thus i both expect and hope, there will appear more support specs in the game. and i would suggest mage is one of the most suitable roles that can have a 4th spec for it.
if you’d say “why not priest ? why not druid ? why not shaman?” etc… i am with you. let them have a 4th, 5th spec for support roles too !
Aug has failed so far. Don’t think they are in a rush to add any more support specs until they can fix Aug. If they didn’t buff tanks and healers it might work.
In my opinion, mages could have a tank spec that incorporates spells to buff armor - similar to the Sorceress’s Frozen Armor, Shiver Armor, or Chilling Armor in D2. They could also enhance physical damage, like Enchant from D2, or maintain aggro by spamming short-range AoE spells such as Cone of Cold, Dragon’s Breath, Snowdrift, and so on.
A lightning-focused spec would probably work well too. Shamans and Boomkins already use some lightning-based spells, but that’s not an issue - most classes have access to abilities tied to Fire or Frost elements (e.g., Warlocks, Death Knights, etc.).