After adding a twelth team you'll have the trouble of how to split the divisions and what to name them. I propose calling them the Buckeye Division and the Wolverine Division. In the unlikely event that the annual Ohio State vs. that school up north game doesn't serve as the year's conference championship game an additional game can be played between the division winners.
The Big 10 really needs a 12th team and a title game. OSU and Michigan ended their season ranked #1 and #2 in the BCS. Florida then beat FSU in Tally and won the SEC title game, thereby grabbing enough attention to jump Michigan into the Corn Chip Bowl. We know what happened next.
The media constantly presses for Notre Dame to join the Big 10, but if that would really work, it would already have happened. They need a team that presents a well rounded athletic program and adds a TV market. Louiville fits that bill and would also bring an annual rivalry with the SEC. Rutgers and Syracuse should also be considered. A suggested lineup would be Michigan, Michigan St, Northwestern, Purdue, Wisconsin and Minnesota in the “Lake Division” and Ohio St, Penn St, Illinois, Iowa, Indiana and Louiville in the “River Division”.
If that had been in effect last year then OSU and Mich would have played each other twice. Two weeks in a row. I don't kow if that would work. I don't think either school will want to give up that big game.