"Corporation Service Company" a company that has registered domain names for Square Enix in the past such as MindJack, Nier and Gun Loco has registered a domain for Final Fantasy XIII-2: www.finalfantasy13-2game.com is the website. It is unknown whether this is just Square Enix protecting the domain or if it will be a legitimate game in the future or if it is the new title for Final Fantasy 13 Versus. With the franchise Square wanted to make out of FF13, anything is possible. However, nothing has been confirmed at this time.
Still waiting on Final Fantasy XIII Versus.