Looking at the schedules, I would say the winner of OSU/USC, OU and possibly Clemson have the best chances of running the table.(though Clemson never seems to be as good as people anticipate) Missouri has a fairly decent schedule as well, but I just don't see them winning in Austin, even if it is a down year for the 'horns. I also have a very hard time seeing OSU winning @USC as there really is no team who shows up better in big games than the Trojans. Plus, I can't help but suspect that OSU is once again overrated.
Just to give everyone a heads up about the SEC for this year: I expect it to be a "down" year, relatively speaking. There are a ton of new QBs that will be broken in this year, and there is a very real possibility that an SEC team could go undefeated. Georgia has a chance...but they have a brutal stretch of away games at the end of their season (LSU, UF, Kentucky, Auburn - all in a row), plus away games at USC and ASU earlier in the season. UF also has a chance if they can beat UGA. I wouldn't be surprised to see the UGA/UF game have two undefeated teams in it.