I suspect that there have been extensive surveys but without the Nokia name on the survey (just on the cheque to the survey company). You don't get to be number one by closing yourself off from public opinion.

OTOH, a design your own cell phone website would be a nice PR move. Something where people could offer suggestions for the next generation using the Asus/Intel WePC website as a model (user submissions and voting on submissions).

http://www.wepc.com/