Ok, so here's my two cents.
I play a warrior tank, startet at the beginning of bc, and right now, we're at 11/12 normal mode, with only nef missing.
From what i've experienced, stamina's gotten pretty much useless. In WOTLK, it was awesome, because healers had unlimited mana and the ability, to bring you from 5% to 100% in quite no time, and stamina had the astounding ability to make the difference between a one- and a twoshot.
But now, things have changed. Everyone has a shitload of health. When i am tanking the boss, it feels like this:
The boss hits me for an certain ammount of damage per second. If i fail to block, dodge or parry a streak of these hits, i drain my healer's mana. If i block, dodge and parry a few hits in a row, my healers are able to conserve their mana, channel mana hymns, do what so ever to regain some of it. Having 10k HP more or less never seemed to make a difference. 3% block on the other hand sure does. With every point i stack in avoidance and mastery, i get closer to being unhittable, i increase the chance to block, dodge, parry in a row, and my healers are being grateful for that.
Sure, there's not much except stamina you can do against magical damage. But the Tol-barad Trinket, with its on-use-400-resistance on a 1 minute cooldown helps a lot. Needless to say, that stamina doesn't reduce the incoming magical damage anyways. And from what i've experienced, the magical damage on a tank is never high enough to be really dangerous. At least i've never run into any situation, where more stamina would've been that helpful.
In addition, the more you avoid from the bosses incoming melee damage, the more you can focus on how you have to time your cooldowns to minimize incoming magical damage, and the more mastery you have, the more efficient shield block becomes.
Just one or two thoughts from me, open for debate.
Good night, everyone