Well one, high budget, exclusive game can sure shift the public opinion of a console and sway people towards it. Just look at Halo, GTA, Final Fantasy etc. The thing is I can't think of any big 3rd party games, that could potentially be Wii exclusives, which would do this for the Wii. Red Steel and Metroid Prime 3 look promising but I don't think they'll have the same effect say Halo did for the Xbox. I see Wii sports doing this more than any other game and it's not high budget or third party. That's not to say we won't see some sort of 'Halo killer', as the fanboys like to call it, emerge from a third party. It really depends on Nintendo and how much freedom and support they give to developers. As Davidredge said, they need to lose this kiddy image. If they want a larger audience then they're going to have to buck up their ideas and not shy away from GTAesque games.