No, it's pretty much 99.99% bona-fide. A trailer of that quality is most certainly not a hoax.
Either way, I'm happy with it. it's good that they didn't just target it to the 360/PS3 crowd only, as they've had their fill of "hardcore" games, now there's finally something as a primarily Wii exclusive. Hope it turns out better than TFU.
More proof:
http://www.joystiq.com/2009/01/23/in...ii-ds-in-spri/