But, the thing that caught my eye, through the shaky cam footage and bobbing heads moving in and out of LoS of the video, the character is flipping through what appears to be the blacksmithing menu, and what does he pull up?
He pulls up a pauldron. A single, lonesome pauldron. Not attached to a cuirass, not attached to a piece of a set, but a SINGLE pauldron, denoting that you can indeed change pauldrons through smithing. Or at least this is what it appears to be. I can't imagine any other reason why they would have a single pauldron on the screen as an option to change and forge unless you can change them.
Good news! Discuss. Note that this has been heavily speculated on, because of screenshots and different cuirass/pauldron combinations, but it has NEVER been "confirmed" by a dev, so I think this video gives pretty good proof.
Just for reference, the pauldron that he pulls up is http://www.uesp.net/wiki/File:SR-character-Gameplanet_wLegal.jpg pauldorn, but again, it's JUST the pauldron, not the chest piece, and it's only ONE of them.
No, I will NOT link to the video until a mod says it's ok. So please do not link to the video.