It should be just fine. That damn Wii has already proven it can have fun games even if they're too pixilated to see XD.
It'll probably cater to a whole new niche of people, If BioShock was done for it. Who knows? RE: Overkill did just fine as a rail shooter, and sure, I doubt it would be as good as Metroid as an FPS...
Well, actually...I dunno. Maybe they can strike gold again. The Metroid Prime series did really good in the FPS niche. To me it was like Halo without retardation AND a beautifully designed storyline. Not to mention, at the time, the graphics were incredible.