Crushing blows are being removed. It could be assumed from this, that warriors and paladins are losing one of there biggest perks - being able to not be crushed, whereas druids could (would) be.
After seeing some numbers on Tankspot, of lv 70 warriors with 3000 BV (I'm going to assume thats after the +100% BV from shield block) - I'm predicting that the ghosts of "crushing blows" will return.
In short - Normal hits will be the new "crushing blows". Druids will take 100% of them, Warriors and Paladins will be able to push them off the table using abilities for periods of time - though it won't be the result of mindless shield block spamming. The new shield block gives us a choice of when we need to absolutley not take any normal hits for the next 10 seconds - making us less suceptable to the RNG / allowing us to respond to bursty or raid wide damage spikes.
Shield Block Rating also have actual value to warriors. Without an ability that can keep crushes at bay all the time, SBR will impact our mitigation/avoidance (unsure which I feel its more like).
So in general - more options, more fun. Good warriors will be good because of their intelegent use of shield block, rather then the current situation of bad warriors being bad because they fail to mash it.
My only concern with all this - is the tuning of AoE type/style mobs. Groups of weak melee mobs will either be trivial to tanks (all attacks being blocked completely) - or hit hard enough that they will shread non tanks with their normal attacks.