Increasing the value per point of mastery for paladins or warriors is not hard to do. Likewise, we might shift more of the warrior mastery between block and critical block because of the value of Shield Block.

I’m also not sure we’re that worried about paladins (or anyone) blocking, dodging or parrying every hit. That isn’t the game breaking scenario that it used to be. If in later tiers of gear you manage to do it, probably by giving up on other stats, I’m not sure it’s a huge danger. Sixty percent of damage is still a lot and none of those stats help with magic damage. In a world where two back to back normal hits could kill you, it would be a lot more valuable. In Cataclysm, it might just translate to healer mana savings. We’ll keep an eye on it of course.

We did change parry to scale from Strength. (Source)