According to AmiAmi online shop, the DVD volume 7 of Sengoku Basara Two
will carry an unaired episode. It will be released in April 2011.
According to the official website, short extra episodes of Sengoku Basara Two
will be included in the DVDs. The first episode "Mini Sengoku BASARA Tsukiyo no Katakura-kun" (3min) will be released with the DVD volume 1 on October 6th.
Source: Sengoku BASARA official website