According to Kadokawa, an unaired episode of Kore wa Zombie Desu ka? of the Dead was announced to be released on October 30th. It's designated as the 11th episode and will be bundled with the sixth volume of the manga.
The second series is ten episodes long and started today. The episode 0 of the series will be released as an OVA on April 25th.
According to Neowing, a short OVA of Queen's Blade: Rebellion will be included in each of the six Blu-rays and DVDs. The title of the first episode is "Exposure above the Limit!? Training! Sacred Pose of Annelotte".