An astute reader spotted several more RX 480's on Newegg, lacking clock speeds but providing physical dimensions, albeit with what looks to be a stock image. All three cards seem to be dual slot designs, XFX's card measuring 10" x 5", ASUS' at 11.8" x 5.4" and Sapphire's a wide bodied 11.8" x 6.5". This could indicate a custom cooler or merely that the cards have rough dimensions listed as opposed to the exact size.
Unfortunately the comparison and details page is unavailable so we don't have a way to see the listed clock speeds but we can be sure that they will have three DP 1.2 ports and an HDMI out. We will keep an eye out for any more leaks we can share with you.