There's not gonna be an announcement then - or the rest of this month. As they were twittering earlier this week, "This year's about the 50th anniversary and new Who in particular. Certain people (read: Moffat) don't want that upstaged." When 'The Time of the Doctor' and the Smith/Capaldi regeneration's out of the way, and the fans are waiting for Season 8 to start (presumably in August), that's
when we'll start seeing announcements and releases.