No chance in hell of it getting Geforce Now. Gamestream from your own PC is possible (but highly unlikely), be Geforce Now? Not a chance in hell.
GeForce Now sounds like a "Nintendo-like solution" to the lack of third party support to me. It may be branded differently, but I would bet on it happening if NX really has a Tegra chip powering it.
That'd be a reason for Nvidia to give Nintendo a crazy deal on the hardware.