All of you have been waiting for this. After much debate, the second season of the High School DxD anime has been confirmed.
From the look of the picture I saw with the article, there's no doubt that this season will cover the second story arc, complete with Gasper (the boy with the paper bag on his face on the far left) and Xenovia's (on the far right) first anime appearance. Irina wasn't shown in the pic, but is sure to appear in this new season.
Update: Looks like it's already been talked about in the Talk about Season 2 thread, but since there were too many comments there, I was hoping to start a new thread here.
Update 2: I checked the source of where the news came from (Akiba Hell (Akiba Jigoku). Seems that there will be another episode (episode 14) of the first season released with the 15th light novel on Blu-ray. Like the 13th novel, it will be included with the limited edition version. Expect it to be released in May 2013. Also, there will be a "Boost Box" featuring a Rias oppai mousepad, an artbook (labeled as Occult Research Club Oppai Boost Book) by Miyama-Zero, Hiroji Mishima (illutrator of the manga), and Hiroichi (illustrator of the Asia & Koneko spin-off), and an Akeno pillow cover (sorry, couldn't read the first two kanji before that). So it looks like the first season isn't over quite yet.