According to Mainichi, the airing of Beelzebub
was suspended from March 20th because the content of the anime was considered to be unsuitable to the current situation resulting from the earthquake. Yomiuri TV will air Yumeiro Pâtissière
instead. It hasn't been fixed as to when Beelzebub will be resumed.
Updated on March 28th
According to Mainichi, the episode 10 of Beelzebub was aired on March 27th. Yomiuri TV said the airing could be suspended again depending on the circumstances.