the layouts have changed every trade show. button size, placement, location, titles, color, writing, are all up for change and have been changed many times.
nunchuk has full motion sensor, the front sensor on the core controller is for infared like light gun it tracks movement based on screen position, the motion sensing is just relative to your motions not the screen on both controllers, the IR makes for more accurate pointing. ps and the c and z buttons are on the nunchuk, a and b are on core controller see here - http://en.wikipedia.org/wiki/Wii#Controller
