First of all, I think there is about a 50% chance Swofford pulls a rabbit out of a hat and holds this together by getting ESPN to agree to more money.
If the ACC does blow up completely, I think it goes like this:
UNC, Uva to B1G
FSU, Clemson, GTech to Big 12 with Louisville
VTech, NC State to SEC
I think Louisville gets the nod over Miami. Louisville does have strong football and basketball, and more importantly, has fans. Miami's attendance is abysmal, despite the fact that the team is pretty good this year.
I think UConn gets strong consideration against UNC for the last B1G slot. UNC has the better hoops program and draws a little better than UConn. UNC is also mired in a major scandal, and will be splitting a market with at least one other conference. UNC will pull it out in the end, but the comparison will be closer than most will think. Which won't do UConn any good.
I think there is a meaningful chance that the remaining ACC schools, and several other schools east of the Rockies, say "no mas", and form a new conference. I think the top flight academic schools want no part of paying players, and that is where this is going. I think Duke and Wake may rebuild the ACC with like minded institutions that will be focused on academics first. The key to this would be Vandy and Northwestern. If they joined, and think both would, this academics focused league would be pretty formidable from a marketing perspective. I think a lot of these schools are disgusted by the direction of college football. They don't want to drop to DII, but they don't want to be semi-pro either.
If that happened, the Big East would probably be about the same as planned, less Rutgers and Louisville and plus Pitt and maybe Syracuse.