1. If UGA runs the table, no way in HELL they can be kept out.
2. If OU runs the table, the same can almost be said, except without quite the authority as Georgia. OU's non-con schedule was mediocre to poor, their toughest games are at home, and they'll avoid Mizzou until the Big-12 CCG potentially.
3. If USC runs the table, but #1 and #2 also happen, I think they'd be the 3rd most deserving team based simply on SOS (OU's would be slightly tougher).
Now, if USC, OU, and UF all run the table, this is where it'll really get ugly, as SOS's will be much closer to one another. All 3 teams benefit from very fortunate scheduling where they've all faced their toughest opponents at home and/or have avoided other top conference opponents entirely. I could see OU being left out in this scenario simply because USC crushed OU for the title already and because of OU's recent BCS failures to BSU and WVU. Also, TV ratings would be much higher for a USC vs. UF match-up.