this requires the following:
a Paladin
Dual Spec Holy with 5/5 in Judgements of the Pure
2nd Spec such as ret or prot
Make sure your in your holy spec, judgement a mob (like a rat in icc before a boss) change spec to prot or ret and notice you still have the 15% Melee/Casting Haste for 60 seconds!
Enjoy your extra dps/threat!