If images from NeoGAF and Twitter are to be believed, then the existence of a slimmer PS4 model may have been leaked online.
As evidenced above, the machine appears to have mechanical on/off and eject buttons and a product code of CUH-20XX, which fits with Sony's coding standards. No optical audio port can be found, though it does retain a disc drive.
Nothing verifying the authenticity of the console has appeared in the FCC's database as of yet. Fans will have to wait until Sony's PlayStation event in September to find out whether of not this next iteration of the PS4 is indeed legitimate.