The whole idea of expansion hinges on what The Big 10 does, they aren't taking any teams from the SEC, geographically it wouldn't make sense.
Seems as though they may try and add from The Big East and maybe The Big 12.
Every team has punitive stipulations for schools that try and bail on them, The Big East had to learn the hard way when Va. Tech, Miami, and Boston College bounced. They now have regulations that would make it difficult for a team to leave...5 million dollars and a 27 month notice.
If they wanted to make this happen ( The Big 10, that is ) by 2012, they will have to act quickly ( this summer ).
I personally hope that they add Notre Dame, that way they can have a conference championship game and Notre Dame can quit sliding by on name alone.
If they do add more than 1 team, it would change the landscape of college football, as other BCS conferences would look to follow The Big 10.
I hope this doesn't come to fruition.