Retina Display: a display with a pixel density of 300 or more. iPhone 4's screen is 326 ppi (pixels per inch). iPad's current resolution: 1024x768 27" iMac's current resolution: 2560x1440 If the 27" iMac resolution was put on the iPad (9.7 inches), then it would be 302.81 PPI. It would just barely qualify. So, if you've ever seen the iMac 27", you know how big of a screen that is. In order to gain 'retina display' on the iPad, you would literally be shrinking that screen down to a third of its size, but with the same resolution. Possible? Perhaps. Likely? Eh, probably not. Discussion?