Here is one of the latest rumors to come out of GDC:
"The real NDA breaking rumor has EA working on a Harry Potter game using the mic in conjunction with gestures to cast spells. Now that's the type of Wii title we're talking about! "Wingardium Leviosah" FTW! Sadly, those who attended the EA Wii event on Wednesday signed NDAs -- so there's a lot of people out there sitting on information they can't confirm, deny or share with their readers."
This would be pretty nice to use with a game like Harry Potter. Nintendogs worked with voice command for the DS, I would imagine that a game like this would work the same if not better. We'll see if this rumor turns out true.