A win by Missouri makes them the Big XII champion and automatically puts them in a BCS game. Then the South team that didn't get to go to the Big XII title game would very likely play for the National Title. (against Florida).
I think this is a more disturbing scenario for the BCS folks than they would like to let on. It puts them in the uncomfortable spot of having to choose a team that didn't even qualify for its conference title game into the National Championship game, and that just seems wrong.
But what else can they do? The next choice would be USC based on current ranking, but how? If Oregon State wins out, USC won't win the Pac-10, and how can you choose USC over Penn State, a team that blew out Oregon State? Of course, Florida against Penn State doesn't seem that exciting, so we can probably rule that one out.
Things could also go haywire if OU loses next week at OSU. That would put Texas Tech in the Big 12 title game, and assume then that it beats Mizzou--does Florida play Texas Tech in the National Title game? Or does Texas?
These things usually have a way of working themselves out by the time the title game rolls around, and I assume that it will this year, too. But things could get weird before it's all done.