And yes, the Big XII never really made sense in the first place: the geography was messy, there was a ton of animosity between North and South and very little in the way of tradition binding them together (like, say, what we have in the SEC).
Other blogs and news outlets will handle the ramifications of all this conference shifting far more capably than I ever could. One thing I can handle, though: a historical retrospective of the Big XII Championship Game, which gave us more great moments than anyone realizes.
Oh well. Fare thee well, Big XII. We hardly knew ye.