After reading the proposed battle changes, I have to say that i'm very excited , and i like pretty much everything I read (of course we'll have to see the actual implementation). There's only one thing that kind of irks me, as someone that played tanks in every single trinity-featuring MMO since the outset of the genre, and before themn, on several MUDs:
The proposed hate meter.
In my opinion the mechanics of aggro should remain hidden to the players, that need to be able to read the behavior of the mob themselves in order to tank effectively, and to avoid grabbing aggro if they are not tanks.
On the other hand an easy to read aggro meter turns what is normally a "art" based on instinct experience and ability into a simple mathematical exercise.
My percentage isn't growing fast enough or is being overwhemed? Easy! provoke more! My percentage growing too fast and i'm a damager? Easy! Stop for a second.
All is easy. I have nothing else to do than following the on screen instructions, that act as nothing else than an unnecessary and unwarranted crutch. What was an epic fight is now turned into easymode guitar hero with swords.
The screen says to press red, you press red, it says to press blue, you press blue. Bo-oh-ring.
In the vast majority of MMORPGs hate meters don't exist, and people tank very well without them. On the other hand, when people move from a MMO where this crutch exists to another, they struggle, because the hate meter gets people used to tank easy mode, effectively making them worse (and often lazy, as they do just what's strictly necessary to keep the hate meter on top of the percentage they need) tanks.
I feel that implementing hate meters goes strongly against the focus on skillful play that seems to be the focal point of this combat reform.
First you want to encourage the satisfaction of playing skillfully, and then you add an immense crutch that gives simple on-screen instructions to follow, removing a large part of the skill needed to tank and to keep aggro away in the case of a damager.
It seems absolutely conflicting to me.
Finally, there's the matter of tension. Battles that are tense and somehow unpredictable are more fun. In MMORPGs with no hate meter, the tension created by the fact that the mob could turn on you unexpectedly (or that you could lose aggro if you don't keep the foot on the gas all the time if you're a tank) adds to the fun.
In MMORPGs that have one, the aggro part battle is just a key pressing exercise in which one follows the on-screen prompt to press the correct keys. There's no tension involved, because you KNOW when the mob is gonna turn and on who, before it even does. Again bo-ho-ring.
Ultimately, as much as I approve wholeheartedly everything else I see on the battle changes blueprint, I'm strongly against the implementation of any aggro-crutches, including the hate meter, as i know for a fact (as I tried it elsewhere), that it'll be a surefire way to lessen my fun and enjoyment in my chosen tanking role.