As I post this, there will be approximately a day and a half left until a NEW entry to the Tales of Series will be revealed. See the countdown site here. Basing it on the countdown, the new title will be revealed on September 14, 2011 at 5:00pm Japan time, just a little bit before the start of Tokyo Game Show 2011.
No news yet on whether this will be a mothership game or an escort title.
In the meantime, let me just browse the countdown site's codes and flash file to search for clues... Well, nothing in there. Judging from the structure of the message though, which says "New" Tales of instead of the usual "Next" Tales of, this new game will most probably be an escort title, and not a mothership title. There have been rumors floating around that this upcoming game might just be for the PlayStation Vita. And also, looking at the font itself, it seems they're actually using the font used in Tales of Destiny and Tales of Destiny 2... Take from that what you will.