Well, Ohio State has a legitimate chance of making it to the Championship game if they can survive their schedule. OSU somehow worked their way into eight home games and only four away games, but two of those away games (Iowa and Wisconsin) could turn out to be brutal.
This is probably one of the deepest years for the Big Ten in awhile in my opinion. Ohio State, Iowa, and Wisconsin all have a legitimate shot at making the National Championship game if they win out.
Iowa has to go to Arizona and play a pretty solid Arizona team, but they have all the other major threats to win the Big Ten at home. Though it will be interesting to see how they do against Northwestern this year considering their losses against them the last two seasons. I think Iowa has the easiest road to win the Big Ten with their schedule and their long list of returning starters.
Wisconsin has a pretty weak non-conference schedule, but they do have to travel to Iowa, as well as Michigan State. They get Ohio State at home, so that should make things a bit easier on them. They have a good number of solid returners, and they have a good chance to start the season 4-0 before they are really challenged.
Ohio State has three big roadblocks in their season, Miami at home, and then going to Iowa and Wisconsin. If Pryor can keep up his Rose Bowl performance level, then things should be looking up on offense. The defense lost some solid starters, but the one thing about Ohio States defense is they always seem to have great players laying in waiting, so we'll see how their defense holds up.
Other than those three, the other teams that I think have a chance are Penn State and possibly Michigan State. Penn State still has major questions at QB, but Evan Royster should be able to carry some of that pressure on his shoulders. Penn State still has to go to Ohio State and Iowa, as well as to defending National Champs Alabama (going to visit three BSC bowl winners in one season is almost unfair) but if they manage to pull off the upset at Bama, they should definitely be in contention then. As for Michigan State, they've been improving pretty steadily in my opinion, and they get Notre Dame and Wisconsin at home, but have to go to Iowa (who they barely lost to last season) and Penn State.
Either way, the Big Ten should be really interesting to watch this season.
As for the rest of the nation, things seem a bit too up in the air for me to really tell how things might turn out. Florida, Texas, and Oklahoma all have to replace long-standing starting QBs, as well as lots of other starters, so it will be interesting to see how they handle the change. Alabama has to rebuild some of it's defense but still has most of it's offense, so we'll see how they can handle this season.
Boise State has a legitimate chance of getting to the National Championship game if they can get by #6 Virginia Tech in their opening game and Oregon State in their third week. If they win those two games, I wouldn't be surprised to see them ranked in the top three. I also know I'll be paying alot of attention to Nebraska this year to see what is coming to the Big Ten next year. Also, in an unrelated note, I would find it hilarious if the National Championship game is Nebraska versus one of the Big Ten teams.