So I've been on the PTR recently. Because of the free respecs I specced retribution, euqipped my hammer-lol, and then set out to check out the changes for myself. In short - wow. Read on for my full "review".
Now I want to tell you I wore 2 pieces of season 1 holy gear; a mage cloak; a ret hammer and blue ret pvp legs; and a hell of a load of holy pve gear. And let me say this - it was still awesome. The conversions in stat mechanics help a lot. Especially the spell crit merge. If you didn't know, spell crit and melee crit have been combined to be simply crit. This means my holy gear suddenly had a lot of crit for my lovely hammer to deal. As sis my judgements. I think this is far better, as the previous problem with a ret paladin was the balance between spell and melee. Too much melee enhancement, and you suffered because your judgements, hammer of wrath, seals, etc. weren't dealing enough damage to make up for 2 handed weapon speed. Too much spell damage, and you lose all your melee power, crusader strike power, etc. So this means crit itself balances, and there is little compromise.
Also, spell damage has been changed. Bonus healing and spell damage both now come under spell power. Again, this helps a bit because now you can affectively heal yourself when needed. This may sound like a "So what?" situation, but remember this: the talent "Art of War". Increases the crit damage of your judgements, crusader strike and divine storm by 10%/20%. This is good, but the healing comes in next: the first point reduces the cast time of your next flash of light by 0.75 seconds. That's half the time, math fans. And the great bit? The second point in gives your next flash of light an instant cast. And this happens when you critically hit with those spells it mentions. Combine this with a larger crit chance, and this procs quite often. In a raid, this means you can top yourself up enoug health to stop the healer having to move to you. It really is very handy.
This is also very handy in PvP where you're fighting constantly and you can suddenly throw in an instant heal to keep yourself topped up.
Another thing that changed is the way seals and judgements work. Seal of justice and the crusader have been removed, but now all seals do base holy damage when judged. They still do what they did but now it's just holy damage on judgement. However, judgements now remain on the target for a few seconds, and seals now last 2 minutes, without being removed by using judgement. Handy for mana conservation. The judgement spell has been split in 3: Judgement of the Wise (similar to seal of wisdoms previous mana regen judgement), Judgment of Light (similar to seal of lights previous health regen judgement) and Judgement of Justice (the replacement for seal of justice, so now any seal can be used for the same effect when needed.)
Judgement of Light is what I find myself using most. The mana regen now with talents and what-not, means that my health went down slower than my mana. What health I did use was restored when I hit the target after using this judgement. But judgement of the wise would probably come in useful in raids, with another paladin applying light, which would really help tanks and other melee dps. Judgement of justice dastically reduces movement speed and prevents Npc's from fleeing, which is great for a bit of cc every now and again, and great in pvp. Run now, mage.
The judgement switching and what not seems a bit confusing at first, but it becomes instinct after about 5 minutes.
Finally I want to talk about divine storm. This is a melee attack that applies holy damage to 4 targets within 8 yards, and also heals any 3 party/raid members in range for 20% of that damage. I'll let you absorb that. Nice isn't it? There really is no reason not to have a ret paladin in a group any more. Oh and of course this has it's critical strike damage increased with art of war, which means a hell of a lot of damage. In my opinion, this is slightly better than consecrate, if only because it deals more damage at once, and is more controllable. If a polymorphed mob wandered into your consecrate before it was a nightmare. But this lasts a considerably shorter time than consecrate and thus as long as your not in range of said sheep/pig/turtle/penguin then you should be fine.
So in conclusion, I think the seals and judgement has been buffed for better management; divine storm is a great spell; stat changes (itemisation) allows for better spec balance; and art of war is very handy.
Oh and I almost forgot. Auras now affect whole raids, not parties. Woo!