If the Michigan State Spartans defeat the Wisconsin Badgers in the Big Ten Championship game, they go to the Rose Bowl as champions of the Big Ten. It's as simple as bowl scenarios get, and their fans probably don't want to think about the other ones. Mostly because the other ones involve them losing the Big Ten Championship game, and most of their fans don't believe that's going to happen.
Michigan State Spartans blog The Only Colors decided to explore this question anyway. What happens if the Michigan Wolverines don't finish in the top-14 in the BCS standings and the Spartans lose this weekend?
If Michigan can't get BCS eligible, they're being selected by either the Capital One or Outback, most likely the Capital One. Nebraska will probably be snapped up by the Outback. This leaves the Insight Bowl in Tempe, and they take MSU...The Spartans will probably face Kansas State in that game.
Michigan State's life gets a bit easier if the Wolverines don't end up BCS eligible, but that's dependent on a variety of factors currently outside of Sparty's control. The best solution to this problem is to win the Big Ten Championship and let Wisconsin worry about these scenarios.