Dunno the status of the plant itself.. According to the dates given by the original news reports it shoudl be at least partially back up & running.. Mid-Feb was the date given for partial production running partially off of paint facilities at the neighboring plant. Full production was scheduled to resume in April.
However, I know they decided not to produce anymore of the NB bosy style Miatas and just go ahead and replace the tooling with NC equipment.
If my memory serves me correctly, the Rx-8 and Miata were the only US market cars made in that facility, so I don't think Mazda6 schedules woudl be greatly affected.