A Japanese magazine scrounged some new screens of Final Fantasy XIII. Yes, the characters conform to the Squenix design standards, which mean either you can't tell their gender or they actually belong to both.
A few sites got their grubby paws on 'em, Smashpad is one publishing in English, so let's go over there and have a look.
And while, ordinarily, I'd now pass off someone else's wisdom as my own, realize that I would be quoted in the Wall Street Journal as a source on live childbirth before I'd ever sound authoritative on Final Fantasy. And Fahey's off duty. So here's their analysis:
There are a few details about the game we have been able to decipher despite knowning no Japanese. There appears to be a very prominent red-headed female character that is reminiscent of Rikku from Final Fantasy X. The gameplay screens are hard to decode, as the menu system looks a bit different and disjointed by comparison to previous FF games. Also, FFXIII appears to stay the course set by FFXII by showing enemies on the field rather than throwing players into random battles.
New Final Fantasy XIII Screens Surface [Smashpad]