The official Japanese FINAL FANTASY XIII-2 website has been updated today with a few bits of new information, including new wallpapers and a new keyart for the game. In the new keyart you can see Lightning, Noel, Serah, Moogle (bow mode) and Mysrious Man.
The new wallpapers included Lightning & Serah keyart and Noel, Serah & Moogle renders! You can check them out below, but wallpapers are just in 1280×720 so if you want bigger you must visit the official site.
FFXIII-2 