I'd put Kentucky's chances of leaving at somewhere around 10 percent, tops. A much more possible scenario would be Missouri heading to the Big 10 and being replaced by Arkansas, who has never truly fit in here (although the Arkansas-LSU rivalry is finally starting to heat up).
Let me preface any of the following by reminding folks that a big part of the reason Arkansas and South Carolina entered the conference painlessly the last time was neither team had an in-state rival sitting there ready to veto the deal. Keep that in mind when adding teams from states that already have a SEC team.
Also, any scenario that involves ejecting Vanderbilt isn't realistic. Vandy takes a beating in football, but they get paid for it and it funds everything else they do, and they're not leaving. Plus, the other schools appreciate the occasional breather when playing them.
And we're off...
1) Tulane. Positives: Used to be in the conference, gets the SEC back into the Superdome four additional times a year, has a sterling academic reputation. Negatives: Isn't competitive, at last check didn't even have a marching band, has low fan support and doesn't bring a lot to the table in terms of traveling for bowls. And LSU would have a cow if it even came up. Odds: 50-1.
2) Houston. Positives: Nice facilities, emerging football program, huge TV market to tap into. Negatives: Texas is not the Southeast, still some bad aftertaste from the John Jenkins debacle, no traditional rival. Odds: 10-1.
3) Southern Miss. Positives: Has played every SEC team so much that they're practically family already, built-in rivalries in-state and against UA/AU. Negatives: Both Mississippi schools are already scared to death of them and there's no way they let this one slide by, not to mention facilities are not top-notch. Odds: 40-1.
4) TCU: Positives: Good fan support, strong football team, already plays a SEC-style game. Negatives: Again, Texas is not the Southeast, private school with facilities that trail in a lot of ways, no traditional rival. Odds: 20-1.
5) Louisiana-Lafayette. Positives: Excellent fan support for the level of school in question, long history playing SEC teams, has its own tradition and a bunch of them already have a built-in hatred for LSU over the school's name (tried to get it called "The University of Louisiana" once but LSU interests in the state legislature killed the idea). Negatives: Small stadium, small dollars, big objections from Tigah land. Odds: 50-1.
6) Georgia Tech. Positives: Prodigal-son program, great tradition, great academics, lots of history. Negatives: Younger Atlanta is now largely a UGA town, UGA would probably poop a brick if this suggestion came up, South Carolina also wouldn't care much for elevating GT's recruiting profile. Odds: 8-1.
7) Memphis. Positives: Large city, decent-sized athletic budget, good facilities, great secondary programs (basketball, etc.), and in the event of Kentucky leaving would replace a rivalry game on UT's schedule. Negatives: Despite not really being in UT's recruiting sphere, the Vols wouldn't want this. And if it's Arkansas that leaves and not UK, UT would be overloaded with rivals. Also some academic questions about the school in general. Odds: 20-1.
8) Clemson. Positives: Pretty much the most SEC-like of the ACC schools already. They already play South Carolina every year, so there wouldn't be much of an objection from the Gamecocks, and they actually fund their other programs. Negatives: Really none from the SEC's end. Odds: 5-1
9) Florida State. Positives: Good basketball and baseball programs, fertile recruiting territory. Negatives: Lots of NCAA attention lately, no more Bowden draw, Florida seems to regard them differently than USC does Clemson. Odds: 10-1.
10) Central Florida. Positives: Emerging program in a growing market, starting to make waves in other sports. Negatives: Football has spun its wheels a little lately, Florida is in no hurry to legitimize another in-state recruiting competitor. Odds: 30-1.
11) South Florida. Positives: Good fan support for a young program, large student base and they travel well. Negatives: Still mostly a commuter school without a lot of national prestige. And see the comments about Florida and UCF and apply them here. Odds: 40-1.
12) Louisville. Positives: Great basketball program to go with the football program. Stadium is one of the nicest anywhere for its size. Name recognition is better now than ever. Negatives: If Kentucky leaves, Louisville won't be interested, but if Kentucky stays, can Louisville get in? Odds: 15-1.
13) NC State. Positives: Opens up North Carolina as a SEC state, no objections expected from the other schools (other than perhaps UT over recruiting territories). Negatives: Traditional rivals remain in the ACC, path to a championship gets harder in the SEC. Odds: 25-1.
14) East Carolina. Positives: Football program has achieved a bit of respect, no objections expected on rivalry grounds. Negatives: FB team is basically all they have, small fan base, sort of a glorified Southern Miss. Odds: 40-1.
15) Virginia Tech, Florida International, Florida Atlantic, Louisiana Tech, Louisiana-Monroe, Arkansas State, Troy, UAB, Miami. I'll give you 100-1 for this entire group.
Scenarios: If Arkansas leaves and the replacement comes from the east, Vanderbilt moves to the Western Division. If Kentucky leaves and the replacement comes from the west, it gets tricky. Auburn could very well move to the Eastern Division, which would mean Alabama would have to drop either Auburn or Tennessee as a regular opponent. It would probably end up being Tennessee that got dropped, sad to say.