The title sounds similar to Sonic Riders or perhaps Sonic Riders: Zero Gravity. Both games were originally released on PlayStation 2, Xbox, Gamecube, and Wii, in the case of Zero Gravity. According to the concept art, Jet, one of the Babylon riders from those two games is also in the game.
The twist in Sonic Free Riders is twisting. Using Kinect, players jump, turn, lean, and twist to control a hoverboard. Throwing, shaking, and swinging are used to toss weapons, like bowling bowls, and activate powerups.
In addition to Sonic, Sega confirmed Tails and Dr. Eggman as playable characters. Sonic Free Riders is slated for late 2010.