In a press conference yesterday the Ministry of the Interior announced that the requirement to carry a breathalyzer or ethylotest in vehicles circulating on French roads has been postponed indefinitely sine die (without a date).
The measure was originally scheduled to take effect in 2012 had already been pushed forward to March 2013 due to supply shortages of the device. It has now been left in limbo awaiting the pronouncement of the National Council of Road Safety. Some say it is destined to be scrapped altogether. The lack of reliability of the devices are apparently the main source of concern.
UPDATE: Breathalyzer is back to being mandatory but without a fine. See post here