Square Enix have given away a set of exclusive art plates of Lightning, illustrated and signed by Tetsuya Nomura himself, to Square Enix members in Japan with Ultimate status.
Oddly enough, he left the following message: "She must not be forgotten."
Whether this refers to her upcoming role in Dissidia Duodecim or perhaps a sequel to Final Fantasy XIII is as good as anyone's guess.
Here are a couple of photos of said art plate, it's quite lovely.
Source: Neogaf