The TPS of Warlock and Shaman is higher than warrior and they scale amazingly. Druid got their TPS increased and rogue is following. Paladin threat is also in a decent spot.
Basically, warrior threat is close to vanilla level like you said. The problem is that the damage of everyone else is now closer to Molten Core level. There is simply no way for the maths to add up. The crutch a warrior is using to keep up with those insane damage is mandatory windfury + mandatory Aspect of the Alpha and even then warrior TPS is still lower and he will often be forced to taunt outside of mechanics simply to reset aggro of some good DPS.
Give deep prot increased threat like a passive +% hit or more threat if you have a shield equiped on One-Handed Weapon Specialization and we would be happy to tank.