Where is Villanova, Notre Dame, and Georgetown at? They would be involved.
I think if a split like this were to happen, ND would probably attempt to align themselves with the other BE football playing schools just for the fact that they would probably suffer more by playing hoops in the A-10 (eg: lower RPI, less chance at a postseason berth) than in the BE (though if their current season says anything about their future, this would look like a moot point). Of course this would probably come with the stipulation that the BE allows them to retain their football independency (or have Weis suffering from a Willingham-esque fall from grace, which means ND would probably not be as gung-ho to avoid a conference affiliation). Otherwise, ND could probably seek out the Big-10 or join the other non-fb schools in a new conference or revamped A-10.
Villanova's standing would probably hinge on their football future. If the economy does improve in the next 5 years to the point it could be reasonable (and desirable) to upgrade their football, they may consider going with the I-A BE members. Otherwise, they would probably join the non-fb schools. Georgetown, on the other hand (I'm going on the thought that they don't offer fb scholarships, I'm not too sure about that though) would more than likely just bail with their other non-I-A fb counterparts. I just don't see a fb upgrade for them to be reasonable at this point.