If you haven't figured it out yet, this isn't a new IP.
Rabbids Rumble has been announced for release on 3DS this November, as reported by a recent press release.
The game itself is a mini-game collection in which "the wacky Rabbids have been let loose throughout seven different worlds and players must battle it out in-game to capture over 100 Rabbids and complete their collection." The game utilizes the 3D and AR capabilities of the 3DS within its gameplay, and features multiple game modes, such as a solo campaign as well as multiplayer.
Rabbids Rumble also introduces a new turn-based combat system. Players can challenge others to battles mixing tactics with the Rabbids' "classic wackiness."
Finally, the press release revealed that SpotPass and StreetPass will be available in game. The SpotPass function is used to download new and rare Rabbits to add to the player's collection, while the StreetPass feature allows players to compete in battles to unlock items and Rabbids.