Here in Europe and especially in germany (not so much in switzerland) this killer-games thing has been a big issue during the last years, and this could increase with the wii. as far as i know, red steel can't be sold to people younger than 18 in germany and i think most of the wii-fps will experience the same.
If this gets a subject in the media, this could become a problem for nintendo, because casuals don't distinguish between the various consoles, which means that they call the wii "the new playstation" and they don't know about nintendos kiddie-image aswell.
but if this is only discussed by gamers, it could even help nintendo, because a big issue for nintendo here during the last two generations was their kiddie-image, which made it uncool to own nintendo-systems.
Essay Pro