I honestly hope you're right Satorri. i think that the current tanking dynamic is reaching its breaking point. You can only continue to make the fights a matter of taking bigger and bigger hits before the margin for error becomes so small as to be a little ridiculous. If you run with 45k health and the bosses are hitting for 40k, you are now at a point where your healers never do anything but spam heal the tanks (we're already at that point), and tanking itself becomes an extremely one-dimensional role: get enough EH between armor and stamina to survive the big hit, and that's that.
what's happened to avoidance is a perfect example: it doesn't matter to a healer how much avoidance you have, relatively speaking. once you get past a certain level of content, you can't simply wait for the tank to take damage and then start healing. you have to assume that the tank is going to take damage before your heal lands and cast while they're topped off. if you wait until the hit lands, the tank will probably drop before your heal goes off. this basically means that even if the tank avoids the hit, and your heal is just overhealing, you still can't afford to miss that heal in the event that the tank doesn't avoid the hit. this means that healers need to basically have endless mana pools, yet another thing that blizzard is trying to find a way to make less trivial.
they've come up with some great ways to make tanking and healing more interesting in the past. i'm looking forward to seeing how they move forward on solving the problem of making boss tanking less one-dimensional.