Let's take a look at exactly what they did and then discuss what it means.
Keep in mind that changed like Charge and Intercept once again no longer having diminishing returns on their stun effects are still in place; these are just additions to the patch notes since the last go around. (If you go to the complete 4.1 patch notes, you can see the entire warrior section is by now quite extensive.) What we can see right away is that much of the changes to protection (Spell Refection duration, the loss of Gag Order's silence on Shield Bash without adding it to Pummel, Sheild Mastery no longer affecting SR) were made to nerf protection in PvP. In one case (the Shield Mastery change), it's actually a buff to PvE tanking, as SR doesn't work on quite a few boss mechanics that the new reduction to magic damage should work on, buffing Shield Block for boss tanking. The Glyph of Spell Reflection is now significantly more powerful, proportionately speaking, than it was.
It's not surprising to see Pummel and Shield Bash streamlined this way. Pummel had a shorter cooldown and could be used in two out of three stances already; might as well complete the ability rather than having two nearly identical spells in the arsenal. The lack of extending Pummel to Gag Order does surprise me, however, even with PvP concerns in mind. It's a big loss for PvE tanking warriors.
Meanwhile, the Juggernaut change, combined with the removal of stun DR to Charge, is somewhat of a buff (trading 2 seconds of stun for 2 seconds sooner to Charge again), and the Lambs to the Slaughter change is a straight-up buff, making it so that arms warriors will almost never have to hit Rend again between Mortal Strike and Thunder Clap (since Blood and Thunder means that TC also refreshes Rend.) The change to Strikes of Opportunity should also increase arms' damage output and keeps mastery a good stat for them.
Fury also gets a pretty significant buff in Flurry's new increased haste, tuning up damage output and rage generation at once. This is most likely intended to compensate for the lost damage from Colossus Smash now only lowering armor by 70%, another PvP-inspired nerf. However, this buff is pretty well offset by a savage nerf to Unshackled Fury, a mauling 6% reduction in the base mastery granted by the specialization. This reduction means that while every point of mastery on gear will have the same baseline effect it does now, a warrior who currently has 18% mastery will be taken down to 12%, a rather huge loss. With these two changes, I find myself wondering if crit has become the absolute killer stat for fury warriors now. It seems vastly unwarranted - a reduction of 2 or 3 points would have sufficied, six is just brutal.
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