Ahh, the old healthpool vs mitigation chestnut. I dislike specs based around huge health pools and nothing else, but in endgame scenarios that's sadly usually the best option. I sort of agree with Lunar regarding needing to see the actual figures of STR/DEX mitigation, but from what i've seen testers find (like 40+ strength needed to boost block mitigation 1%? And needing similar Dex to gain 1% parry/block) I'm inclined to believe that Str and Dex arent providing enough mitigation per point to be noticeable.

The question that DOES need to be asked though - compare a 30 STR paladin to a 30 VIT. Ignoring the block amount... will his damage be noticeably higher? How much of this damage increase will translate into threat too? One thing we don't know at endgame -yet- is DPS requirements for fights and how much threat well-geared DPSers pump out. I doubt 30 strength will make a difference, but if actually holding aggro becomes a bigger issue for tanks, Str might still have value.