We still don't know if there's going to be season 2.
As of August 1, 2012, it has been comfirmed that an Ao no Exorcist movie will be released at the end of the year. (fact) Also, season 2 has been highly considered and recommended due to the popularity of the first season and the cliffhanger left by the many unintroduced characters. (This information [Season2] was collected through research from fans, rumors, blogs, comments, fansites, etc. Therefore, it has not been confirmed and cannot be used for fact, only evidence.)