Paladin hasnt been nerfed. They are still the most imba class in the game.
Loads of people have complained that exorcism is no longer an instant cast, but can still be instant cast as long as Art of War is active.
Also the seal of Curruption & Seal of Vengeance only add the debuff to target when using auto attack or by dropping Hammer of the Righteous on the target, but the damage has been modified to inflict 33% weapon damage with 5 applications and the Holy Damage inflicted by the seal is critical.
The only draw back to the Paladin is that all seals are now judged as melee attacks (where as before some judgements were ranged and some where melee) and have a chance to be dodged or parried.
Also, Vindication has been altered to be an attack power debuff on the target and Seal of Command does less judgement damage but increased melee damage.
So when you look at it, where they have reduced an ability on one side, they have (for a change) balanced this on the increase at the other end.
As long as you keep Art of War up your Seal of Command and Exorcism will do more damage and still be instant cast.
Hope that helps :)

If you are talking 3.2 I thought they had.

But its the opposite. Hand of reckoning now deals about 3k dam for me and as long as I have art of war up (which is 90% of the time) exorcism is still instant, so overall I have gained an extra hit.