Gamertell has posted a photo of two Soulcalibur IV faceplates for the Xbox 360. These look to be unique for press or other promotions. From the article:
"The first is a green faceplate featuring the little green guru himself, Yoda, who is a playable character it the Xbox 360 version of the game... There are two images of Yoda, one with him wielding a lightsaber across the power button and another, larger image that takes up more of the plate but is a but obscured by the disc slot and forehead cropping.
The second is more blue with crystal emanating from the power button like an explosion and the faded face of a character at the far let (or the top, depending on your system's orientation)."