Nintendo will use it where it makes sense. As I said, Zelda is supposedly going to use it. Obviously there is no real use for it in Mario Galaxy 2, or NSMBWii unless they make radically new control schemes for these games. The Zapper was made for 3rd parties, as Nintendo doesn't really make shooters, but Sin & Punishment may be compatible with it.
Until we hear of new games from Nintendo, it doesn't look like they have any plans to use them. But if they do make a game that lends itself well to one of the peripherals, I'm sure they will add the support.