On my iPhone4, even though it's a 'retina' display, I can still notice the stair-stepping in movement. Still photos look great, but from a video perspective, 'r

On my iPhone4, even though it's a 'retina' display, I can still notice the stair-stepping in movement. Still photos look great, but from a video perspective, 'retina' isn't necessarily an accurate descriptor. This is less true of full-motion video than it is of scrolling in an application. As thrilled as I am about pixel density on modern portable devices, it will benefit them to go higher still. The returns are diminishing, but they are there.