According to Tim Griffin:

 The Longhorns have claimed the Big 12 title

Here's the Picture of the Wall

I thought this was insane.  I didn't even think someone would let them do this but hey, I guess its there wall.  I could see if they put up a Big 12 South champs since they all 3 were tied but a big 12 champs thats a little too far.  I was thinking about what Mack would say to a recruit when they go by the trophy case and he only has 2 trophies but 3 years listed.  He could let them know that Oklahoma is holding it for him