> How interesting: by moving some of the driver to firmware, Apple has effectively made it easier for OSs like Linux to have good support for the hardware, because the OS<->hardware protocol operates at a higher level of abstraction and may work across multiple chips.

If I am remembering right, this was the original idea behind UEFI drivers too — you could in theory write drivers that the firmware would load and they would present a simpler/class-compatible interface to whatever operating system was loaded after that. I think Apple did pretty much this on Intel Macs for a number of things.