Since I don't care for JRPGs anymore, I wouldn't personally see any difference if it completely bombs or if it is a 10/10 game.
And if the game comes out bad, there won't be many naysayers here - they'll simply say that the next release due out will be the good one, the big one. Amazingly, less than 1/2 of the "this is a sure-fire AAA release" releases end up being really good standout games.
Square is conservative in so much that they aren't going to drastically change the game and bring us something completely new. This means that they're likely to maintain their current sales trends, but they're not likely to make some huge splash and change people's minds. Most people who have decided to buy FF 13 will and it won't attract the attention of many who aren't interested or don't know anything about it.
You need innovation to attract new attention to your product. For example, Grand Theft Auto 3 was fresh and new in a lot of ways, at the time, and because of it Rockstar brought an entirely new audience to their series. Now they're protecting it by being more conservative.
