It looks like TCU and Baylor will again be the class of this league this year, toying with going undefeated. If that is the case, only a TCU victory will land a Big 12 team in the playoffs.
OU and UT look a year away from contention. That means that a Big 12 team will have to earn it's way in rather than be given the benefit of the doubt.
Ohio State and an SEC team are probably shoe-ins for 2 berths. The PAC-12 has improved by leaps and bounds and will take the third berth. That again leaves the Big 12 champion competing with the ACC champ (likely FSU again) or the SEC or Pac-12 runner up.
That is a tough battle for a conference champ without an end of season championship game strength of schedule bump. This situation is a horrendous recurring disadvantage for the Big 12 every year.
If TCU wins that game, starting the season highly ranked and the perception that TCU belonged in the field last season and was screwed will see them in.
If Baylor wins that game, the memories of Baylor's last two bowl game debacles will keep them out and the Big 12 will expand before the next season starts.
UT and OU are looking at 2016 and will not be screwed out by no championship game.