Neither Final Fantasy XIII nor ingenue star Lightning will go away as Square Enix has announced an unprecedented second sequel to the RPG, though rather than call it "Final Fantasy XIII-3", they elected to dub it Lightning Returns: Final Fantasy XIII and promise it'll be the final chapter of that particular series.
In the press release, the publisher announced, "Square Enix, Inc., the publisher of SQUARE ENIX interactive entertainment products in the Americas, today unveiled the final chapter to Lightning’s saga at a fan-filled 25th anniversary event of the FINAL FANTASY franchise. LIGHTNING RETURNS: FINAL FANTASY XIII, due out next year, incorporates a brand-new story, world, characters and an enhanced gameplay system."