I thought the whole point of the "Retina display" is that it reaches the threshold of pixel density where you can't see pixels anymore (at that distance from the screen).
6.1" seems more the size of a small tablet than anything fit for a phone. Assuming people hold a tablet about the same distance away from their eyes as a phone, perhaps even farther, what's the point of having an even higher pixel density? Isn't this going to cause more design problems than it provides marketing benefits?
Higher resolutions will still be needed for implementing autostereoscopic 3D displays[1], where multiple angles of a scene are displayed at the same time.
Unlike 3D displays that use active glasses to time-division multiplex the viewing angles for each eye, autostereoscopic displays use parallax barriers or lenticular lenses to multiplex the images inside a single 2D image, reducing the effective resolution per angle/eye.
6.1" seems more the size of a small tablet than anything fit for a phone. Assuming people hold a tablet about the same distance away from their eyes as a phone, perhaps even farther, what's the point of having an even higher pixel density? Isn't this going to cause more design problems than it provides marketing benefits?