I read a post a couple weeks back on The Rivalry, Esq. about Big 10 expansion. In theory there really is only three ways the conference can expand and have a chance at survival, expand to 12, 14 or 16. 12 is what most think they would expand to but for purposes of showing you how conferences could go extinct, let's say the Big 10 expands to 16, and succeeds.
The reason I believe the Big 10 really could succeed with 16 teams where the WAC could not is because all the teams that would be added are huge TV draw-ins (such as if people see Louisiana Tech playing and they see Notre Dame playing on different channels, they are going to watch Notre Dame). The teams that would make the most sense are: Texas, Texas A&M, Notre Dame, Nebraska and Pittsburgh. All of these candidates are huge draw-ins and all have recently good football programs (except for Notre Dame, they had a down year last season). Think about how good the Big 10 really could be, you could have Michigan, Michigan State, Ohio State, Iowa, Penn State, Wisconsin, Minnesota, Notre Dame, Texas, Texas A&M, Nebraska and Pittsburgh all in the same conference. I think I would love to play with that kind of competition...
For the SEC, they lost no one and probably could gain alot from the ACC. Best candidates would be Miami, Florida St., USF, and Georgia Tech. They all bring TV markets in and adding 3 more Florida schools to the only one they currently have definitely would help. Florida State and Georgia Tech would be in the West Division and USF and Miami would be in the East Division. The SEC would most defintely improve.
The only issue now is that this leaves BCS conferences and Non-BCS Conferences in a state of rebuilding. Most conferences would probably go extinct like the SWC did. Others like the MWC could probably survive by adding a couple of WAC and C-USA teams or maybe poaching them completely and making themselves into a 16 team conference. Sun Belt would actually probably survive because no conference would be willing to take in one of their teams to stay alive. WAC, C-USA and MAC would either have to invite teams from FCS to stay alive or go down to FCS level.
Bottom line: If BCS Conferences decide their is more opportunity in 16 team conferences we could see some major changes in College Football.