If I am reading the reporting correctly, then the B1G game selection will be:
#1 Fox at noon
#2 NBC 7:00 pm
#3 CBS 3:30
just picking a week at random, 10/8 weekend the B1G games are:
Nebraska-Rutgers
OSU-Michigan St
Wisconsin-NW
Iowa-Illinois
Purdue-Maryland
Michigan-Indiana
So OSU - Michigan State would air at noon on Fox, NBC will show whatever game USC plays, and CBS picks up a table scrap of...Wisconsin-NW? Michigan-Indiana? Yeesh.
It is hard to see how they are going to have 3 top-tier matchups to offer their 3 main network partners each week (even when USC and UCLA come on board), but having access to Ohio State/Penn State/Michigan/USC (and smaller but still solid brands like Wisconsin/Michigan State/Nebraska/etc.) on a weekly basis I guess was good enough for them (not to mention each of the networks is going to have a shot to show the Big Ten Championship game in at least one of those years over the life of the contract). That's a lot of die-hard football alums at those schools (even if they have produced some mediocre football outside of Ohio State over the past decade).
This deal also seems to imply that more Big Ten schools will end up on Notre Dame's future schedules (assuming the Irish re-up with NBC), so you could see a Notre Dame at Michigan or a Notre Dame at Southern Cal game end up in primetime on NBC as well, where as those games currently would air on ABC/ESPN.