There was a bit of an uproar earlier this year following the registration of a Final Fantasy XIII-3 domain. Square Enix rep Akio Ofuji has finally addressed the situation on the Square Enix Channel radio show claiming that Square Enix's Japan office didn't even know the domain even existed.
Square Enix's US office were the ones who originally purchased the domain name as a precaution. Ofuji then issued a statement about the domain registration after voice actress Asuka Nishi requested a role in the title. Nishi said that she had heard about it on the internet and called up Ofuji about it whilst he was vacationing in France.
So perhaps this means Square Enix might be undecided about the development of Final Fantasy XIII-3 and might instead choose to start working on Final Fantasy XV instead. Only time will tell. Be sure to check out our Final Fantasy XIII-2 preview from a couple weeks back!