We need to be mindful that while evocation is an accepted part of the Arcane spec because all T6 are about mana regeneration it could be a change that all specs will need to manage mana in a proactive way rather than passive.
IMO It would be a major failure on blizzards behalf if spec dictated this talent spend
Rune of Power: Fire
Incatner's Shield Frost
I agree. The way these talents are set up, I see them as being a major mechanics change to all mage dynamics. The sheer fact that an entire tier is focused on one spell makes me think that they're bringing some extra dynamics to the class. Rather than the same basic principles being kept for all specs (and changing only certain rotations or casting combos) mages appear to be getting their own identity where it might be possible for a fire mage and a frost mage to play drastically different, eve before endgame content. However, will these talents gear towards a certain spec, a certain boss, or a certain playstyle? I'm not on beta, therefore, I don't know the answers to these questions.