I just scoped out the All Star: Bats board at DC, and they have an excellent explanation for the title

Batman is actually Marv in disguise








Miller has apparently already commented that this is meant to be DKR continuity aswell......









"Now TV's all about format these days isn't it, and I've got a new type for you right here. Its me and Paris Hilton driving around in a car.... Now I know what you're thinking, but she's in the boot!" "So you see, 'Ring around the Rosey' refers to the horrible symptoms of a terrifying disease, a disease which.....a disease which....ZIM! Theres a Pigeon on you're head. You have 'Head Pigeons'. get to the Nurse before they spread to the other children." "Get off my lawn Cookie Beast!" --Invader Zim