Just speculating, but what if Mario Kart Wii and Mario Kart on the DS shared alot of the same tracks and you could play against each other online? That would be sweet, to compete online on the DS or the Wii against other racers on a DS or Wii. This is very unlikely, but it might happen. I think it would be kinda cool, although there are 100s of factors saying it would never happen.