The Art of War is a two point talent on Tier 7 of the Retribution tree that increases the Critical Strike damage of Judgements, Crusader Strike, and Divine Storm. For PvE, that's a simple DPS increase that scales properly while in PvP, it helps to counter Resilience. Ideally, however, the number should be tweaked to completely negate it as Resilience damage reduction from crits is capped at 25%. The damage bonus is a good buff for the three main damage sources of a Retribution Paladin, but the better part of the spell is the reduction in the cast time of Flash of Light.
With the changes in Wrath, Retribution Paladins are no longer gimped healers and Flash of Light can heal for decent amounts. The buff lasts for 15 seconds and provides the Paladin with healing flexibility both for herself and for allies. The important thing is this: it allows Paladins to heal while moving. In PvP, particularly, Retribution Paladins must always be on the move. Because it can proc from three sources -- with talents that contribute to higher crit chance such as Conviction and Fanaticism -- the buff should be up quite often, although it should be pointed out that casting Flash of Light will consume the buff.
An instant heal, despite activating the GCD, is easy enough to insert into the spell cycle without disrupting DPS too much. The beautiful thing about this is the flexibility that it offers the Retribution Paladin. Think about it as a health potion that has no cooldown. This allows Retribution Paladins to be somewhat self-sustaining in encounters, even contributive heal-wise. Of all the versions of the wonderfully named The Art of War, this is the one I like best. Hopefully this talent sees it all the way through to release with very minor tweaks. Talents like this go to show that the nicest talents aren't always the fancy activated ones but sometimes the most simple.