We have already learned that a movie of Ao no Exorcist was announced last year, and according to Takeda Seiji (竹田靑滋), the chief producer of MBS (毎日放送), the movie will be premiered at the end of 2012. Apart from the movie, Takeda Seiji also mentioned that he would very much like to work on the second season of the series when the original Manga chapters are enough for the production.
Judging from the producer’s word above based on the fact that you have actually read the Manga, we can tell you that the TV Anime is totally different from the story of the original Manga, at least the second half of it. Thus even if there would be a second season, the story should be a bit different. We will keep an eye on this. Like the series, you can check out the official website of the movie for more.