It's more of a novelty than anything tbh as is all the undead/demon abilities that paladins have. However about the only useful thing I have ever done with it is aoe pull undead/demons for some major aoe aggro. Healadins can get a decent use out of it too inbetween heals when it's on CD.

Of course it's really fun in shockadin gear in MH to go all out on holy damage inbetween heals. You won't outdps the mages or anything but you'll out dps the melee :P