Deca Sports on the 3DS now has a name: Deca Sports Extreme. Thanks to Hudson, we also have a full list of all ten sports in the game. Deca Sports Extreme comes with Soccer, Tennis, Basketball, Ice Hockey, Snowball Fight, Sumo Wrestling, Bowling, Snowmobile Racing, Sport Blowgun and Trampoline.
Each sports event has its own special power-ups that allow you to perform special moves like a giant racket in tennis or a cannon dunk in basketball. The game also allows you to customize your team of players.
Hudson say that Deca Sports Extreme will support up to four players over local wireless. They plan on rolling the game out sometime in Summer 2011. You can find screenshots in this previous post.