Now, I don't know if this was just a joke for the first of April or if this is a downloadable character. It seems like just a joke but I know it would be fantastic if it were real. I'd buy it (and I never buy character/costume DLC!). Konami does have a record of silly things in their games though such as having Rumble Roses characters available for download for their numerous Metal Gear Solid online adventures.
Silent Hill has also shown up in a dance game before. In Dance Dance Revolution EXTREME there were two music videos featuring the horror game.