Yeah, as long as a game benefits from motion/IR controls, it's fine. These controls shouldn't feel forced or gimmicky or tacked on. They should add something to the game, make it more immersive, intuitive. They have to be thought-through and well-implemented. And, above all, they should actually WORK.
As far as games that HAVE to have motion control (or more specifically, IR), it'd have to be shooters. Not necessarily First Person. Just shooters in General. There's just no going back to analog sticks once you've tried IR aiming. :p Oh, and the pointer should become standard to navigate through menus and interfaces, too.
2008 Predictions:







