Unfortunately my hopes for FFXIII are really really low. The series went downhill after FFX in my opinion. The later games didn't feeel like a Final Fantasy game after all the ones I played (played since FFI on NES). While I consider them to be good games, they lost the path that had me pretty much interested in the series. I believe the later games became a cinematic story with a game in it rather than a game with a story. The graphics are amazing, the combat look awesome.... but the appeal is not one of a FF game but from another RPG. I'm starting to think that if the game was not called a FF, it will not have that boom and hype, you know.
For the tales Series, I played since Phantasia and it has been a breath of fresh air. While the story is not as solid as the FF series (and in many cases is soooo predictable V_V). I have been most impressed how they have focused on the battle system because there is still much more room for new ideas while keeping what isn't broken. Putting Dawn of the new World aside (good game but it had "recycled spinoff" written in many places) the series has evolved nicely and improving in time and my interest has been constant. (need to get an Xbox360 or PS3 to play Vesperia though)
My take I expect more from Tales of Graces than FFXIII even though the later will be a huge, HUGE seller