Mariokart 3ds will feature underwater levels!

Source Nintendo's official E3 trailer
I'm excited myself what about you guys

No so much. I love Mario Kart and I will get this game for sure, but I doubt there will be much speed underwater. Same for the glider. I doubt you can speed up with your car in the air.

But we will see how it will work out. Can't wait and hopefully a goomba will be a raceable character.