Okay, just got done playing all 8 new tracks. They are fantastic! I was cat Peach on the Link bike with the Link kite. Son was Link on the B-dasher, tri-force wheels and the Hyrule kite.
Track 1- Yoshi Circuit- Super fun. It's always been a great track from the game cube and in the wiiU it has been shined up!
Track 2- Excitement Arena- The jumps are jumptastic. Cat peach was adorable with her kitty paws and Link's sword has his sword for all the tricks.
Track 6- SNES Rainbow Road- An old favorite, the music is wonderful. The mountains in the distance change colors, matching the pixel you roll over, which was neat.
Overall, totally worth it and we were very excited to play.