They've already said they are strongly against adding more utility to the classes in order to make them more competitive for raid slots, so I also don't think that is going to happen.
The changes to the tier will probably be damage spells / cooldowns. Which are hard to balance. I'm open to being wrong (and hope that I am) but past trends of balancing don't support major changes like a tier overhaul which has the potential to completely change how each spec plays mid-expansion.
I know what you want to happen, it just doesn't seem realistic based on previous trends.
My main question to you right now is: Are you ok with tier bonuses alleviating the major concerns of the specs?