Motion controls for MP3 where excellent and you could customize them to your needs. Maybe the only game with much more options to customize your game play was The Conduit but honestly, MP3 played very good with those motion controls. MP1 and 2 controls with the game cube controller where great too, so the best option would be to allow both control options and let the user decide. But imo, Motion controllers is the best way to play a FPS. It's the most realistic way to play. PC controls (keyboard and Mouse) are very accurate but not realistic
Anyway, i'm sure Nintendo will allow the option to choose between motion and regular controls