I really hope the NFC capability is used to redeem coupons and vouchers through the tablet. It would be a really nice way to redeem eShop currency or redeem online codes.
Connected to that, I'd love to have a portable 'Nintendo ID card' so that the game can reconfigure to my account when the controller is passed to me, and I put my card on the screen.
Yeah, I think that NFC for Club Nintendo is very likely, due Nintendo´s obsession for make straight forward things, friendly as possible.