Give it a shot. Look around (and/or survive) long enough, and you'll be able to dig up some official wallpapers. Link can be seen below:
<a href="http://www.us.playstation.com/games/SCUS-97203/" target="_blank">http://www.us.playstation.com/games/SCUS-97203/</a>
<a href="http://www.us.playstation.com/games/SCUS-97203/" target="_blank">http://www.us.playstation.com/games/SCUS-97203/</a>