I was at a friends house yesterday and was playing Mario Party 7 for the Gamecube. Then I thought, why hasn't anyone made a Mario Party-style game for the iPod? I would love it if someone made a game like Mario Party SOON!
I'm guessing the reason it hasn't been done is because it would primarily be a multiplayer game, and at the moment multiplayer on iPhone isn't really much of a big thing... single player is still where it's at.
Konami made a Mario Kart clone using Konami characters. Why not a Mario Party clone? Heck, why not a clone of all the Mario spin-offs?!