Just some random thoughts :)
DOS runs natively in 16-bit Real Mode. EMS, and Himem, memory managers (to my best knowledge) provide their services by jumping in and out of Protected Mode. 32-Bit Protected Mode programs use a DOS extender to jump into Protected Mode, and provide 32-Bit services.
A DOS can be created to run in 32-bit Protected Mode by default, to provide DPMI services natively, to emulate EMS/XMS, provide a bi-modal mouse driver, provide a bi-modal keyboard driver, provide a bi-modal timer interrupt, and intercept Real Mode interrupt calls to translate addresses from 16-bit to 32-bit Protected Mode.
Yeah, the Linux console beats DOS. It would be cool to have a 32-bit DOS kernel able to run 32-bit Protected Mode DOS programs natively. One advantage is to open the possibility of 32-bit device drivers.