[spoiler]He's called "Old Dragonslayer" and his spear's description only says that his armor reminds you of one of Gwyn's knight or something, but yeah it's pretty much Ornstein. Some think it's because, since Anor Londo was an illusion, Ornstein and Smough also were. I didn't keep any screenshots on this computer, but if you want proofs I can tell you that two early bosses are called 'Dragon Rider' and 'The Pursuer', but that's not much proof anyway.[/spoiler]