It's all a bit hushed and secretive, but reports out of GDC say that the new Harry Potter and the Order of the Phoenix game will use the upcoming Wii microphone attachment in some fashion-- the most obvious use we've heard is incanting spells. People are under non-disclosure agreements about some aspect of this game, but not the microphone.
People are getting really excited about the Wii mic, it seems. Excited enough to forget that Harry Potter and the Prisoner of Azkaban covered the mic thing back on the PS2. This one will just be better anyway.
We're just glad the Wii mic is getting use outside of licensed Disney karaoke games. It's covering the whole range of licensed games!