Unless you are talking about some radical overhaul of the concerence system, or a 16 team, month long playoff MSU still gets left out this year. Now, next year they would get a chance to play in the Big 10 Championship. But, then OSU would not get that opportunity and it could actually hurt the loser in the playoff scenario to actually play in the game.
For instance, does an 11-1 OSU get in before an 11-2 Wisky that lost their last game?
The problem with a playoff is that you have to completely take polls out of it. Which means you need to get all eligible teams into a conference system that is equitable and allows for an abbreviated, no more than 8 teams, playoff. 4 superconferences would do it.