What Ive heard from a couple of little birdies is only that Apple has been noodling with increasing the height of the display, keeping the width and pixel density exactly the same as on the iPhone 4 and 4S. I had not heard an exact pixel number for the new height. 1152 made some sense, but doing some math after reading Weintraubs report, 1136 makes a lot of sense.
First, at 1136 × 640, you get a diagonal of 1,303.877 pixels after applying the Pythagorean theorem. There are no such thing as fractional pixels, but what Im talking about here are pixels as a unit of length, equal to 1/326 inch. Divide 1,303.877 by 326 and you get 3.9996 inches. Boom, a 4-inch display. Im sure if Apple instead went to 1152 pixels in height which works out to 4.042 inches theyd still just call it a 4-inch display, for the sake of neatness, but its at least somewhat interesting that 1136 is the closest they could get to precisely 4.0 inches.
Second, aspect ratio. With a 640-pixel width which everything I have heard and seen reported suggests is set in stone there is no way get to precisely 16:9:
(16/9) × 640 = 1,137.777
You cant cut seven-ninths of a pixel. 1138 × 640 would be a tad closer to 16:9, but 1136 × 640 is within five-thousandths of an inch of exactly 16:9. So I think Apple would be safe to bill an 1136 × 640 display as sporting a 16:9 aspect ratio.