I took some pictures of my TV showing Monday Night Football in HD. My digital camera takes pictures at 2592x1944. ESPN is broadcasting MNF in 720p (1280x720). As detailed as these pictures are, a 1080 broadcast would show even more. I took the pictures about 4 feet from the TV.
Check out how much you can zoom in before the image gets pixelated and the clarity of the text. Click on the pics below to see the full resolution versions.