announced in his twitter that there is nothing to worry about the airing of the remaining two episodes of Mahou Shoujo Madoka★Magica
. He said the quality of the episode 11 would be unsatisfactory if it were aired on March 17th. The work rooms of SHAFT have been messed up by the earthquake and they have spent significant period of time in cleaning up the rooms. The recent episodes of Madoka Magica have been completed a few hours before the airing time, so Urobuchi felt relieved to hear about the postponement.
Source: Urobuchi's twitter