Alabama are Iowa are the only 7-0 teams in the nation but Florida is the initial #1 in the BCS Rankings. If Florida continues to struggle against subpar competition I don't see how they can continue to be the #1 team. Alabama has faced a much more difficult schedule, very similar to what Boise State has had thus far this year.
If Boise State wins out like it appears they can, it would still be a longshot for them to make the national championship game. Cincinnati and Iowa both have more difficult schedules than Boise State and if all 3 go undefeated, which is unlikely, Boise State would likely be the team left out. None of which would matter if 2/3 of Florida, Alabama and Texas go undefeated.

USC is the highest ranked team with a loss, but with 4 road wins against top 30 teams that shouldn't surprise anyone

The top 25 teams are as follows.

1. Florida 6-0
2. Alabama 7-0
3. Texas 6-0
4. Boise State 6-0
5. Cincinnati 6-0
6. Iowa 7-0
7 USC 5-1 (with 3 road wins against top 20 competition)
8 TCU 6-0
9 LSU 5-1
10 Miami (FL) 5-1
11 Oregon 5-1
12 Georgia Tech 6-1
13 Penn State6-1
14 Virginia Tech 5-2
15 Oklahoma State 5-1
16 Brigham Young 6-1
17 Houston 5-1
18 Utah 5-1
19 Ohio State 5-2
20 Pittsburgh 6-1
21 Wisconsin 5-2
22 Arizona 4-2
23 West Virginia 5-1
24 South Carolina 5-2
25 Kansas 5-1