The iPhone retina display is 326 ppi while the new iPad retina display is 264 ppi. If Apple were to release an iPad with 326 ppi, what would the increase be in the pixel density? When Apple went from the iPhone 3GS to the iPhone 4, the screen resolution doubled exactly, making updating the graphics fairly easy for developers. Would things get more difficult in terms of scaling if Apple kept the 9.7" screen size of the iPad put upped the ppi from 264 to 326?