The Galaxy S III's 4.8-inch Super AMOLED display was a mixed bag. Its viewing angles were stellar and its 1280 x 720-pixel resolution meant that you could see more of every Web page you visited, but its brightness rating was on the low end of the spectrum. But for the S4, Samsung may be bringing out the big guns. According to GSM Arena, which cites the aforementioned AnTuTu benchmark screens, the S4 should come packing a 4.9-inch, 1920 x 1080p display with a pixel density of 441 pixels per inch.
Previous rumors had the S IV coming with an unbreakable flexible AMOLED display, however, according to The Verge, those seem to have been debunked rather quickly.
Sources: GSMArena, The Verge