Grand Prix San Diego falls on Nov. 12th and 13th, the weekend before this year's World Championships in San Francisco. For those who participate in the GP, they'll receive this playmat with art from Magic artist Steve Argyle. GP San Diego is being put on by Cascade Games.
Our sponsors CoolStuffInc.com will be there, so definitely stop by the booth when you go.
Update: As has been discussed in comments, this art comes from one of Steve Argyle's designs for the Legend of the Five Rings card game, Hida Iseki.