Welcome: Pittsburgh and Syracuse, who to the surprise of no one moved their timetable for leaving the Big East up a year to 2013 after initially scheduling it for 2014. The arrival of the Panthers and Orange will make the ACC a 14-team league.
Farewell: No one this season.
(Big East) American Athletic Conference
Welcome: A brand-new name, first of all. But where the on-field product is concerned, the upheaval is even more dramatic, as Houston, UCF, SMU and Memphis join Old Big East holdovers Louisville (for now), Rutgers (for now), Temple, UConn, Cincinnati and USF to form a 10-team league -- one that despite its trials and tribulations will still award its final BCS berth in 2013 before another makeover in 2014.
Farewell: Pitt and Syracuse depart, and leave the door open for the next two on the way through. And though they exited the future AAC without having ever played a league contest in any sport, in 2013 the American also says a good-bye of sorts to Boise State and San Diego State, which as recently as last November had been scheduled to become the anchors of the new Big East West division.
Conference USA
Welcome: A whopping six new members, two of which are culled from the remnants of the late, lamented WAC: Louisiana Tech and UT-San Antonio. The other four arrive fresh from the Sun Belt: FIU, North Texas, FAU, and Middle Tennessee State. Add those six to the remaining eight, and -- for one season only -- you get a 14-team league split into two seven-team divisions.
Farewell: The aforementioned UCF-Houston-Memphis-SMU quartet, all off to the American.
Mountain West
Welcome: The last train leaving the WAC station pulled up at the Mountain West, depositing San Jose State and Utah State. After the Spartans' and Aggies' impressive 2012 seasons, this looks like a major boost -- provided their new coaches can keep the momentum going after the departures of Mike MacIntrye and Gary Andersen, respectively.
Farewell: Thanks to Boise's and San Diego State's about-face from the American, no one is set to leave the Mountain West. That boon plus the new additions -- boosting the league to 12 members -- gives the MW the chance to split into two six-team divisions and hold a championship game in 2013 for the first time.
Sun Belt
Welcome: Hello, Georgia State -- fresh from the FCS ranks -- and Texas State, arriving from the rubble of the WAC. The Panthers might take a little bit to get up to speed (they just finished 1-11 in their final FCS season), but Dennis Franchione's Bobcats were feisty (if only 4-8) in 2012, their first FBS season. South Alabama will begin its full membership in the Sun Belt
Farewell: As mentioned above, FIU, North Texas, MTSU and FAU leave en masse for C-USA. Subtract four teams from the Sun Belt's 2012 10-school roster and add in the two new arrivals, and you're left with an eight-team league -- once again, for 2013 only.
WAC
Welcome: No one.
Farewell: Everyone.
Independents
Welcome: It's not by choice, but for a single season, Idaho and New Mexico State will join Notre Dame, BYU, Army and Navy as football teams without a conference affiliation. As part of the transition year, Old Dominion will be an Independent.
Farewell: Despite chatter its timetable might be moved up (or eliminated), Navy remains steadfast to its plan to only join the American in 2015 -- meaning no school will give up independence in football in 2013.