@P.Jay: "So with Wayland depending on KMS I see big problems coming."
and Wayland does not depend on KMS. QtWayland runs on the raspberry pi - proprietary driver, no KMS and still: it works. Wayland is just a protocol to exchange buffers.
You are not the only one getting it wrong, there is lots of FUD around Wayland especially as people get confused about what Wayland allows and what Weston (reference implementation of a Wayland compositor) requires.
I don't see any reason why Wayland should not work with NVIDIA's driver and personally I'm sure that the driver already supports it in the NVIDIA labs.