This occurred to me the other day - I bought Wii Music as a present for a younger relative, and some of the screenshots on the box reminded me of the (very basic) music composition elements of Mario Paint on the SNES. Was anyone else a fan of that? I know it was a bit simplistic, but I loved it as a young'un ;-)
Would a mouse accessory for the Wii be silly? I can imagine some cool use of the Wiimote as a graffiti spray can or similar (I think someone has made a hardware hack of this...).