I think you might have a situation where the Big 10 is basically blocked by the Ohio River and Ohio-Pennsylvania boarder, they might go for teams in their 'region' when expansion becomes a reality. They're blocked out of the North East and New York TV markets, but to @ejspsan's point, they can still go west, after schools like Nebraska, Missouri. They could even go after North Dakota State if that school wanted to move up to Division 1. They could also go after Northern Illinois, Ball State, Bowling Green, Eastern, Central or Western Michigan as well.
If the ACC loses Maryland, I think they'll look to replace them, possibly trying to pick off a team from another conference. The Big 8 could expand with some of the schools it's considering now as the Big 12, BYU, Houston, Rice. Wichita and North Texas might be possible as well.
I think in the future the East Coast Conference could step into Big 10 territory recruiting Cincinnati, into ACC territory with Old Dominion and East Carolina, and into the Big East by trying to pick-off UConn and Villanova. Remember, Howie Long went to Villanova. Buffalo, Marshall, South Florida, UCF, Army and Navy could be future targets as well. One in SEC territory might be Memphis.
I think without trying to canabalise the other conferences, the SEC could pick up the likes of Southern Mississippi, Louisiana Tech, Florida Atlantic and UAB. Some of the Sun Belt schools might be considered.
I think the PAC-10/PAC-12 would try to expand with Mountain West schools. especially Air Force.
My thoughts,