The Big 12 and SEC, at least in football, are going to have to get used to each other, since the two conferences reached an agreement that would pair the the champions from both leagues in a postseason bowl game, so long as the teams aren't competing in the four-team playoff beginning in 2014.
Thing is, the conference champion from both the SEC and Big 12 could very well be in the four-team playoff every season, and this new agreement allows for another "deserving" team to make it in its place. This means the Longhorns and Aggies rivalry that everyone had written obituaries for this past year might could be tucked away if the Aggies in some wild chain of events found themselves at the top of the SEC.
But more importantly, as noted by SB Nation's Jason Kirk, this "creates a very clearly defined upper tier in college football, with everyone from the ACC on down all but walled off from the highest level."
The agreement between the two conferences is a five-year deal following the 2014 season.