4 - Custom chips that allow "True" Multitasking.
Like a GPU? :-P
Most computers today have some sort of custom chipset. The problem is that these chips are not used properly by todays OSes.
But anyways.. Who in reality decides what makes an Amiga, is the owner. If they want the ack or whatever to be an Amiga, then it will, no matter how we feel about the issue.
Not that it will ever be released anyways..