I honestly like the Physical buttons more then on screen, but that's kind of a plus for android. They made a point a couple months ago to say that the OS can be configured either way using physical or using on screen. Its up to the manufacturer. ICS is not moving away from physical buttons, the nexus shows off the fact that it doesn't have to have the buttons.
I see. I thought they were moving away from that. I hope it's true that the on screen buttons can be shown/hid by swiping the bezel.