And with the advantage OSU currently has, with a win over a top 10 MSU, they're in.
The Big Ten hasn't been very good this year. Additionally, neither has the SEC. The preseason bias in the polls has helped them immensely in dominating the rankings; for example, Texas AM is #24 with a horrific defense and zero top 25 wins; their best win is against a crappy Ole Miss team. South Carolina lost to a horrible Tennesee team. Missouri has 1 top 25 win. Florida started the year at #10 for Pete's sake!; they're God awful.(yes I know they had injuries, but they still had a very anemic offense prior.) Alabama is great. Auburn is good as well, and Missouri looks good too. LSU is over rated, and so is South Carolina. The SEC has a few very good teams, but depth wise, they're not nearly as strong as recent years.
OSU better get in if they win. If not, college football has completely turned into a joke.