Why don't we wait to find out what actually caused the crash before following a knee jerk reaction and calling for the grounding of the world wide fleet.
The pitot probes changes have been stated as precautionary and until evidence proves otherwise that's what it is, a sensible measure.
While I am very surprised (shocked) that a modern airliner could have icing problems with the pitot system I am still not ready to accept this as the cause just yet, especially as the investigators are infering that the aircraft broke up in flight.