There are rumors that Versus will be rebranded as Final Fantasy XV.
I guess that would at least ensure they're going to finish it. And it certainly didn't look like it had anything in common with XIII anyway.
Not to mention stupid. FFXIII Versus was supposed to follow the same concepts of FFXIII and FF Type-0. Namely the whole crystal, fal'cie, Focus, etc etc.
they gave ffxiv a second chance (though they were probably hoping to recreate ffxi, the most successful ff, with that). if it was cancelled i'm sure it will be reborn
as a social browser game or something because that's totally the future