According to the Sporting News, here is the way the new Big 10 with 12 members will schedule:

"For now, each team will play all five teams in its division once as well as its protected rival every year. The other two games will be a rotation of the other five teams in the opposite division that is not the protected rival. Delany did say the league is looking into adding a ninth conference game, but that change wouldn't come until 2015 so teams can satisfy existing non-conference agreements. "

Michigan will play its protected rival, Ohio State, the last game of the regular season.

Seems like it might work for a model for the expanded Pac12 with a "zipper" plan and protected rivals.

Here is the link.