Forum users are saying it's an icon for Perfect Dark on XBLA, though it could be anything, really. We should also mention that Rare does like messing with fans. Remember that Christmas card debacle? This could be another tease that goes ... nowhere. Also, how do we know that Rare isn't developing a game called "Person Stuck in White Room"? Hey, it could happen!
Regardless, we contacted Microsoft about the possibility of Perfect Dark on XBLA. The company's response: "We have nothing to announce at this time."