I was in Game yesterday trying to get hold of Godfather (they didn't bloody have it!) and on the tv behind the counter they had a preview of a game called 'Wii Music'. By the looks of things u use the wiimote to control orchestra's made up of mii type characters. Also had a video of some guy using two wiimotes to play the drums.
Can't imagine its a game that would appeal to most (including me) unless maybe it comes bundled with a wiimote as an alternative to Wii play for new wii owners?
It said it was coming soon but to be honest I've not seen anything about on here or other gaming sites.