They have been available since the middle of September, as the nvidia-beta-driver package. The update to the stable series came out just today, so no surprise we haven't got that one yet (will package it in a couple of minutes though)
There is an as of yet still unresolved issue with NVMe controllers and this kernel series, so it won't be updated until that is fixed.
No idea, I haven't been following that one.
edit: ninja'd by DataDrake 🙂