Well, because the PSN Store is still offline in Japan. Thus, the Armored Core V closed PS3 beta is now being delayed. It was originally slated for July 1, but is now dependent on when the PSN Store goes back online in Japan.
The Xbox 360 closed beta is schedule to start on July 19 in Japan and end on August 1. The game will be released this October in Japan.
ARMORED CORE V CLOSED BETA TEST | FromSoftware [FromSoftware via オレ的ゲーム情報]
Follow it only does wait please on Kotaku 