Nintendo kept Takt of Magic under wraps, but the now opened official site gave me a better idea of the project. Players wave the remote like a wand and trace patterns to cast spells. This set of movies demonstrates the system. Click on the elementals (wind, earth, fire, water) to watch them.
The page also reveals another tidbit — Takt of Magic is a usually a single player game, but if you use Nintendo Wi-Fi a second player can join the action. The multiplayer system isn’t explained (it’s barely mentioned!), but if this has online co-op I’m interested.