There are currently 25 teams left at this point in the season that are unbeaten(6 of those have yet to play a game).
The following are all teams that have played at least 3 games.

Primary Advantage-Top defense in the league at this point, only giving up 137 yards per game. Offense controls the ball with a balanced attack, third in the league with a T.O.P of 17:33.
Primary Drawback- The Big 12, not much competition in this conference and with a weak OOC schedule the Sooners will have some unanswered questions come season end.
When might they lose?- Sooners go undefeated, depending on how other teams finish it could still be tough for Oklahoma to garner a national title game spot.

Primary Advantage-Andrew Maxwell, one of the top QB's in the league with a passer rating of 232.7. Also a secondary with sticky hands, third in league in defensive interceptions.
Primary Drawback-Maxwell didn't do well with the pressure of a big game, against Notre Dame the QB threw 3 interceptions. If he can stay composed in the big games MSU could play for a title.
When might they lose?The Big 10 Championship game will be the only real test of the season for the Spartans.

Primary Advantage-Solid defense, stopping the run(allowing only 47 yards on the ground) and pass(allowing only 160 yards through the air, picking off over 3 passes per game).
Primary Drawback-The offense, ranking 79th in the league. The Hokies are winning with defense now, but that defense hasn't really been tested thus far. Top caliber offenses might prove too much.
When might they lose?The hokies travel to the swamp to face the high powered offense of the Gators. Florida wins, 31-21.

Primary Advantage-The running game. A&M is putting up 175 yards per game on the ground. Big wins over Alabama and Arkansas make for a nice resume'.
Primary Drawback-The passing game. Manziel has as many picks as TD's(5). A good run defense will put too much pressure on Manziel, which the sophmore won't be able to handle.
When might they lose?The Aggies roll into the SEC championship game against Georgia. The Bulldogs stop the Aggies on the ground and come out with a big win.

Primary Advantage-The offense can play, putting up 38 points per game. Max Wittek has looked good so far with a passer rating of 228.5 and 1324 yards.
Primary Drawback-The Trojans biggest win was against a solid Arizona St. team but it was eeked out in a 120 point shootout. Could USC fair well against some of the nations top defense?
When might they lose? Notre Dame and UCLA remain on the schedule. USC slips to one of those teams.

Primary Advantage-The running game is big. Lache Seastrunk is the star of the offense. 763 yards on the ground with 109 receiving and 12 total TD's
Primary Drawback-The schedule. Opponents are a combined 7-19 and the Bears have had trouble winning. Barely edging out most of their 6 wins.
When might they lose?Week 11, Baylor travels to Norman to take on the Sooners. Baylor loses big, but still have a chance at a BCS game if the Sooners play in the National Championship game.

Primary Advantage-The Badger have shown they can control the clock, leading the league with a T.O.P of 18:38. Defense has also come up big, allowing only 8.67 points per game.
Primary Drawback-We haven't seen much from Wisconsin yet, they have only played 3 games without a real test.
When might they lose?Wisconsin biggest challenge is pending to be played against an unbeaten Ohio State team.

Primary Advantage-The Cougars have a well balanced team. A good scoring defense, a good quarterback in David Piland and a good run game.
Primary Drawback-The biggest problem so far is of course the conference and as of now a combined opponent record of 3-15.
When might they lose?The remaining schedule gets tougher, Louisville and SMU give the Cougars a true test.

Primary Advantage-Big offense, the Buckeyes are averaging 434 yards per game. Braxton Miller has put up 856 yards on only 47 attempts.
Primary Drawback-Ohio State has only played 3 games and those have been against sub-par teams. The defense had troubles with those teams.
When might they lose? Wisconsin will give the Buckeyes their biggest challenge of the season.

Primary Advantage-The Bulldogs have put up big wins thus far in the season, knocking off three top 25 teams. Quarterback Aaron Murray has carried the team with 7 TD's to 1 Int.
Primary Drawback- Those big wins haven't been convincing enough for most voters, but in the SEC any win seems to be a big win.
When might they lose? It looks like Georgia is headed for the SEC title game. Getting a win here will send the Bulldogs to the national title game.

Primary Advantage-Quarterback Garrett Gilbert, the top rated QB in the league has thrown 16 touchdowns to 4 interception in only 79 attempts.
Primary Drawback- The American Athletic Conference. The Mustangs schedule isn't much to be proud of.
When might they lose? The final game of the season is against the AAC's other top team;Houston.This will be a close one.

Primary Advantage- The Bruins are putting up 33.5 points a game with a balanced attack, only turning the ball over once per game.
Primary Drawback- UCLA is 39th in the league in defensive turnovers ranking near the bottom of the unbeatens.
When might they lose? UCLA has a tough schedule ahead of them; Oregon, Arizona St. and USC. The Bruins lose at least one of those games.