Given the rankings there is also a crappy possibility:
Texas wins out. Seems to be a decent possibility.
Missouri wins out except for Texas, with loses only to Nebraska and Texas. Has to beat Ok St, Colorado, Baylor, Iowa State, K State, and KU. Other than Ok St (hurting now) and Kansas, very doable.
Nebraska can realistically now lose 2 conference games and still go to the title game. (tough games vs Tech, Oklahoma, and Kansas). But goes on to lose Big 12 game vs Texas. Last minute loss drops us in the rankings.
Missouri (still decently high ranked from beating Ok St and winning last 5 games) leapfrogs us to play in a BCS game and we are left out.
Just letting my mind wander...