I went to the offcial website and i saw something interesting.
Here (scroll down to "ヘタリアWorld Series まるかいて大感謝祭DVD情報公開!!")
You know the 2nd seiyuu event ? (9th January)
The DVD will be released on the 28th April 2011.
(Do I have to put the cast ?)
That all ! Bye o/