Speaking of Hibiki, the preview seems to indicate a Hibiki episode. On the other hand it seems to trick us into believing she was misled and lost during the challenge. But if anyone remembers during this episode they mentioned they'd post a video of Haruka hitting her face with the box lid as well as the results of Hibiki Challenge.
http://www.idolmaster-anime.jp/namassuka/index.html
If you check the fake Namassuka! page at the bottom left there is the Haruka video and the right a flash animation congratulating Hibiki for reaching the goal and thanking the fans for cheering her.