Page 2 of the supplementary file that goes along with Falcom’s financial report released today has the following information posted in it:
The long expected sequel to Sora no Kiseki, Zero no Kiseki, and Ao no Kiseki will be released. with the page marking 9/2013 on it.
This cements the rumor going along with the Ao no Kiseki rerelease in December. Beyond this info, there is no information other than the fact that it’s coming- nothing on a specific date, platform, or the title itself. I imagine that we’ll learn more about the new title fairly soon, however.