The Wii controller may necessitate the use of some game-specific controllers that wouldn't otherwise be necessary, but the converse is also true: with the Wii controller, some games that would otherwise require a specific controller no longer need to. You mentioned Samba de Amigo, which is interesting, because a new Samba de Amigo is coming to the Wii. I'm sure it will use the regular Wii controller -- that's probably the reason it's on Wii to begin with. Were it on 360, Sega would have to make a new maracas controller. Look also at Ghost Squad, which on another console would need a separate light gun controller, but on Wii it's not necessary.