The Big 12's only realistic "steal" from another BCS conference is if they can convince Louisville to jump ship from the Big(ger) East. In order to do that they would need to add someone like Memphis (a long-time rival) that would help "bridge" the geographic gap.
Louisville and Memphis to the North along with Missouri, Kansas, Kansas State, and Iowa State would mean Louisville and their newly upgraded 63,000 seat stadium would be able to compete with Mizzou as the "top dog" in that division. Adding both of those basketball schools would also increase the marketability of the Big 12's hoops (which is already pretty damn good too).
Neither one of those programs get much in the way of TV revenues in their current conferences, so going to the Texas-dominated Big 12 would actually improve their lot. $3 million per team that plays both football and basketball in the Big East and around $1 million for Conference USA members. Even getting Longhorn and Sooner table scraps would increase that payout. The bowl game options would get a lot better as well.
Right now Big East football is only relevant because of Pittsburgh and West Virginia. No other teams provide much marketing punch and it is debatable that even Pitt does that. Being in a league with Texas, Texas A&M, Oklahoma, Kansas, and Missouri would certainly be an upgrade.
The Big 12 would gain through addition by subtraction as well. Eliminating some of the power of the Big East would counteract the addition of TCU to the Big East, it would force the Big East to add another Conference USA member (Central Florida, East Carolina, Houston, etc) further diluting their football product. Taking away one of the premiere basketball programs would also hurt the Big East. The Big East TV contracts expire after the 2013 season and they will begin negotiating soon. That would be 3 years before the Big 12 can redo theirs, and it is possible that the newly expanded Big East could approach Big 12ish numbers at that time. Making the move now would cut the revenue potential for the Big East to take up some of the market, in addition to weakening the Big East's football power around the time of the BCS evaluation criteria.
That is much more likely "food for thought" than the Big 12 sweet talking a team away from the SEC. Craig James needs to go sit in the ESPN toolshed and think about how much of a tool he really is.