Well there is still a lot of people absolutely clueless about GPL so any joke about this just feeds the FUD Microsoft and others pushed few years ago (about GPL being viral, communistic etc.). Well they need to provide sources only to their changes to GPL stuff (if any). And only to customers who actually bought the device, not any random person on the net. If they simply took N800 box from Nokia and added their proprietary application, they can just point to Nokia repositories. Even documentation that comes with the device should be enough (both Control panel->About and Nokia printed manuals).
Well there is still a lot of people absolutely clueless about GPL so any joke about this just feeds the FUD ...