> I wouldn’t be surprised if we start seeing individual drivers and subsystems move over.

Already happening. https://lwn.net/SubscriberLink/1102982/c3a3a2d4f17108c5/ "Removing binder.c" is an article from yesterday, about discarding the old C implementation of the Android Binder driver (used by every single Android phone) in favor of its Rust reimplementation.