Another week, another series of patch notes to leave me scratching my head and saying "Seriously? This is what we're doing, nerfing the crap out of agility for tanking? Did dodge rating steal somebody's lunch money as a kid? And Shield Block, I trusted you." It's strange to feel betrayed by a core tanking ability. I get why they're nerfing it, since they're increasing the amount of Block value on gear that has to double it's current values, I've already heard Prot warriors and paladins contemplating putting together BV sets for PvP and this change will keep warriors from using SB to get hideous crits in PvP with Shield Slam. At least I think that's the reasoning: I can't believe that anyone was actually worried about Prot Warriors' DPS while tanking in PvE content being too high after the change for 10 seconds out of every 40. Even if Protection Warriors put on every single piece of Block value gear imaginable, that 10 seconds of double damage with Shield Slam would still leave them at the absolute bottom of the tanking basement in terms of damage dealt while tanking.
The agility change is a near non-issue for almost all Warrior tanks: maybe you had Agility as your cape enchant or a few AGI gems, but for the most part Warriors don't stack Agility as tanks. However, since Dodge is at the moment probably the best stat a warrior can stack, the Dodge rating changes will sting quite a bit. (I am aware they're more like a hammer to the back of the head for Druids, but even so.)