Isn't it possible to get the airspeed via GPS through calculations or through the known windspeeds or air pressure from ATC or the MET chart ? I'm not saying GPS should be the primary means of measuring airspeed but as a backup, it's better than flying blind. Morever, most commercial a/cs are fitted with GPS, so not much of a retrofitting to be done.
I wonder what the QRH states for in case the pitots fail ?