> It's like the difference between a 80286 and a 80386: The latter added the hardware support for true multitasking that the former lacked.
I'm not sure this is a good comparison. The 286 did support true multitasking in protected mode, and it was used in many non-DOS operating systems. What the 386 added (among other things) is the virtual 8086 mode which allowed it to multitask existing real mode DOS applications that accessed hardware directly.