Guys. I might be wrong but I think that the Monk's Head Collar seems to be the only piece of equipment that you can only get online, because of all the hours I put into the game I don't remember getting the collar when I did the 3-3 Boss fight in Latria offline.
And the deal with this item is that is that can help you a lot to kill the Blue Dragon and Black Phantom Ostrava fast in the last area of Boletaria.
"Miyazaki asked if we remembered Artorias the Abysswalker. Dark Souls: Prepare to Die Edition will allow people to travel through time to the past and play as Sir Knight Artorias. As you may recall, Artorias never actually appeared in Dark Souls, but we heard that he was one of Lord Gywnâ€™s knights who had learned abysswalking that allowed him to meet the Four Kings. It left me wondering if we will finally discover what prompted Artorias' betrayal... For now, console owners may have to eye the extra content in Dark Souls: Prepare to Die Edition enviously. Miyazaki said that there was nothing he could say about console versions of it at the moment."
I have the impression that there's enough new content to release the game again for consoles, you know, like what happened with Super Street Fighter IV. Only that I hope they put all this new stuff as DLC too.