One of two established precedents will be set--either a 2-loss team or a conference nonchamp will get in.
With how weak overall both the PAC12 and the Big XII have been, I don't think the committee will have a major problem putting in a deserving team that's not a conference champion. The SEC champ (provided it's Alabama) is a lock, as is the B1G champ (provided it's Ohio State).
How's this for a scenario:
1.) Alabama pounds its last two opponents to finish 12-0 as the clear-cut #1 team in the country.
1a.) Alabama then gets shocked in the SEC CCG by 2-loss Florida (say Hurts gets injured early in the game and leaves, but the injury isn't bad enough to wear he wouldn't be ready for the playoffs).
2.) Buckeyes blow out Sparty and win convincingly over scUM to finish 11-1 and the clear-cut #2, yet the Pedsters also win out to win the division tie-breaker and go to the B1G CCG against Wiscy.
2a.) Wiscy beats the Pedsters in a close game in the B1G CCG.
3.) The Coastal division winner (either Clemson or Louisville) gets upset in the ACC CCG.
4.) The Sooners win the Big XII title, yet still have two losses and the home blowout loss to the Buckeyes
5.) The South division winner (likely Colorado, but still could be USC or Utah) wins the PAC CCG and has (at least) two losses.
So, despite their not being conference champions, how do you possibly keep Alabama and Ohio State out of the playoffs? In fact, in my scenario, since Ohio State didn't play and both Alabama and the #3 team (the ACC Coastal winner) lost, wouldn't Ohio State be #1, despite not even being a conference champion?
The Sooners couldn't get in over Ohio State because they have two losses and got blown out at home in the head-to-head.
The Badgers shouldn't get in over Ohio State because they have two losses and got beat at home in the head-to-head.
The team that upset either Clemson or Louisville in the ACC CCG (either North Carolina or Va Tech) will have at least three losses, and there's no way they get in. If the Coastal team that got upset in the CCG still got ick for the playoffs, it sure as heel won't be over a one-loss Ohio State.
The same deal that applied for the ACC scenario applies to the PAC 12 scenario...no way Colorado, USC, or Utah bumps Ohio State.