Jebraltar

Divine Strength is almost completely useless for prot-grinding. Even Divine Intellect is more useful. Once you've invested five points into Holy, as already mentioned, there's no reason not to get Spiritual Focus. Being able to heal yourself with mobs on you is enormously useful, especially given that you probably won't have a big set of awesome tanking gear.

With the buffs that Ret has received, I'm fairly certain that it's now utterly superior for leveling anyway. Prot is just a fun way to level, it's not all that fast outside of a few specific level ranges. (For prot grinding to work, you want large groups of enemies, preferably with slightly low HP and damage, that are clumped up. The murlocs in Dustwallow are the perfect example. Anywhere with casters, especially healers, your efficiency goes down to barely being above that of a 0/0/0 spec.

Edit: I only just now actually looked at the Paladin spec. It's mind-numbingly bad. Conviction has no place in a leveling build, Improved Judgment is mostly going to hurt your sustainability, and Benediction is the only thing you have points in in the retribution tree that's not utterly useless. Prot grinding consists of judging Wisdom/Light on one mob and then sealing Wisdom/Light while Consecration, Holy Shield, Retribution Aura, and Blessing of Sanctuary kill them. Reckoning is a perk, and its biggest advantage is that it doubles your Light/Wisdom procs, not that it makes your kill speeds oh so fast.

Within the prot tree itself, you're missing Anticipation, which is subtracting quite a fair chunk from your survivability at low levels (good luck hitting the defense cap without it in leveling gear) and from your avoidance/block at all levels. Only 2 points in Toughness is questionable, to say the least. 3 points in Imp. Hammer of Justice is a complete waste - HoJ is occasionally useful if you're soloing a mob or something, but if you need to heal more than once a minute, your mana pool will not survive that fight anyway. Ardent Defender is perfectly designed for AOE grinding, and makes for a much better choice than Weapon Expertise. (Ardent Defender is pretty close to a 20% health increase and it also increases the efficiency of any self-heals you use at low life. I've grinded in plenty of spots where mobs would take me down to 35 fairly quickly, and be nearly incapable of getting me down further.) Another talent that would be useful, if you felt comfortable with freeing up the points, would be Sacred Duty - in addition to giving a very respectable stamina boost, it lets you use Divine Shield more often, which means that you can pull bigger groups and be confident that DS will be up so you can use it and bandage.