Wisconsin wins tomorrow, they can easily win out and take the West with 2 losses. Their tough games would be behind them. If Iowa were to win, Iowa could theoretically afford to lose one more game (Michigan) and win the West. A win tomorrow would put Iowa in control of it's own destiny. However, the could not afford to lose another game. But this win would be a big boost nationally.
Northwestern will probably end up with at least 3 losses (Nebraska, Ohio State, and Wisconsin) and possibly Indiana. Wisconsin would be out because of 3 losses (Iowa, Michigan, Ohio State) Nebraska will probably lose to Ohio State and Wisconsin. Which would set up for a nice showdown in Iowa City on November 25th. However, if Nebraska also beats Wisconsin, they would be in control with only one loss.