Thanks to a Siliconera writeup of the TGS demo of Tatsunoko vs. Capcom: Cross Generation of Heroes, we have a better idea what to expect from the fighter's controls, both with the Classic Controller and the Wiimote.

The Wiimote was designed as sort of an all-purpose controller, but fighting games are not something it can handle without modifications. According to Spencer, one button is mapped to combos, and the other to special moves. Holding the D-pad in any direction will change the command mapped to the button. For example, Ryu's special attack button throws a fireball, but up+ special or down+ special will release other moves like the Dragon Punch and Hurricane Kick. It's a pretty admirable attempt at making a fighter playable with the Wiimote.

The "real" control scheme on the Classic Controller is simplified, as well, compared to other Capcom fighters. Attacks are mapped to three buttons, weak, medium, and strong, with no distinction between punches and kicks. In both control schemes, the B button calls the assist character.

Source Nintendo wii fanboy.