Stamina is still by far the most important stat for Prot, especially since we get the 30% conversion of stam to spellpower. At 1000 stamina we have a base 300 spellpower with no spellpower gear or enchants. All of our spells also benefit from attack power now, so strength is now important for a Prot Paladin as well.
Traditional Warrior tanking weapons such as
http://wow.allakhazam.com/db/item.html?witem=29362;source=live are now tremendous for a Prot Paladin, and the enchant of choice is now Potency (+20 Strength) rather than spellpower.
Intellect, Agility, and Wisdom are still pretty much ignored. With BoSanc, mana pool and mana regeneration generally are not an issue at all.
At 70, you still need 490 defense to be uncrittable. Bosses now have to be +4 levels to crush you, which effectively took crushing blow off of the attack table, but avoidance is still very important as well.
At 80, we will need 540 defense to be uncrittable, and this will require +689 defense rating. The tempered saronite armor set has tons of defense on it but no other forms of avoidance, so it will be interesting to see where our other forms of avoidance come from in the late 70's and early in our career at 80.