User blog comment:B214/Season 3 confirmed!!!!!!/@comment-1359322-20141112113539/@comment-24502975-20141112135951

High hopes would be asking for a preview of episode 1 on Dec. 6th

There's a pretty big DxD event going on there, and since even the anime's official Twitter is in on it, we might just get a release date then. If not that, perhaps character designs or other info.