Using Sagarin ratings and simulating the rest of the Big 12 season 1,000 times, below is a summary of probabilities of different outcomes.
First, how many wins do you need to get to the championship game? 2% of the time the top 2 teams were undefeated in conference (9 wins). 23% of the time at least one team was undefeated and 75% of the time the winner had at least 8 wins (with the other 25% of the time 7 wins).
For the second place team, 39% of the time both teams in the championship will have 8 wins - and 56% of the time the 2nd team will have 7 wins. There's a few scenarios where they could have 3 losses (6 wins).
Translating that to results - Iowa State and BYU are most likely to get to championship game, with Texas Tech and KSU next most likely. After those 4 probabilities drop off a good bit.