To get you in the mood for Wednesday’s iPad launch, here is all you ever need or want to know about retina displays as published on TUAW. As for the name, well:
Although Apple invented the term out of whole cloth, it does offer a definition: “the Retina display’s pixel density is so high, your eye is unable to distinguish individual pixels.” That has meaning, and if Apple were to weaselly dilute the definition for the sake of marketing some future product I think we should absolutely hold its feet to the fire.