I checked some preseason rankings and came up with 8 teams for a theoretical playoff.  Lemme know who you think will win each matchup and I'll continue.
1.  Clemson   8  Oregon (Pac rep)
2.  Alabama  7.  Notre Dame
3.  UGA   6.  Michigan
4.  Ohio State  5.  Oklahoma
I could argue for Texas somewhere.  I limited this to two teams from any conference.  I don't think UGA can really end up at 3 and Bama at 2 but whatever, I didn't want a rematch.
Now, these won't be the "final 8" of course, and the outcomes are debatable perhaps outside the top 2.  Who do you have for the Final Four?