The system does still need that Mario 64 level of a game; I think said game needs to show use how two remotes can be the new standard for character control.
I want an extensive level editor that is simply point and click, I want to be able to build areas wall by wall, even poly by poly, upload and download 2D images for textures, create weapons, assign them attributes (elemental, projectile, moving parts, bloom lights, scopes, speed, pre-impact explosive, etc), and most importantly be able to create characters from scratch by either loading up a series of profile 2D images or by molding the character manually in the game like Spore.
I want to be able to go into a menu and select pipes, furniture, vehicles, trees, skylines, architectural styles, sounds, physics, triggers, etc.
A flying game is much needed; I'd put flying in most any game I made if I were a developer on Wii.
I have ideas for games that could not be done on any other system but I honestly won't know if Wii can do it until Nintendo does it first; to use two remotes for character movement. I've talked before about a game where player one controls a large animal using two remotes to run while player two and three chose from a selection of riders that use different weapons; with player one controlling the running and jumping, the other players use two remotes to control their riders' hands (sword, shield, lance, axe, hammer, bow, elemental spells) and everyone can share one screen if playing on the same console.