According to the official website, the releases of Dance in the Vampire Bund
DVD & Blu-ray volumes 2 - 6 were announced to be delayed by one month. Natsu no Arashi! Akinaichuu
DVD & Blu-ray releases were also deferred for three weeks - one month. Bakemonogatari publicity staff said they wanted to air the second online episode by the end of January but there has been no updates since January 28th.
Sources: Vampirebund official website
, Bakemonogatari official website
, Bakemonogatari staff blog