There are 8 legitamite options for the B1G expansion... I will list them from least to most likely:
1) BC
Academics: Good, but it's a private, christian university. Would stick out like a sore thumb among the large state institutions. Yes, we have Northwestern, but they are not religiously based. Much of the sticking points exist here as they do with ND, just with less appeal overall.
Athletics: Boston is a pro sports town, just look at their spring game numbers, pitiful. The university has never shown a dedication to any sport except hockey. As a last ditch 16th member, I guess, but BC will be there at the end if we have to resort to it, no need to make an offer early.
2) NCSt
Academics: Midiling. Worst out of the big 4 in NC and possibly worse than ECU. Not a university that we would be thrilled to have in the CIC.
Athletics: See BC. They only really care about basketball, but not enough to really upgrade their facilities to compete with UNC and Duke. Have some history, but the fanbase support is TINY compared to UNC or Duke. Not really the gateway to the state. Won't get an offer. Might have issues taking UNC if NCSt doesn't have a place to land. If that is the case, we may have to bite the bullet and take them as a package with Duke/UNC. Think the relationship of TAMU and UT.
3) Virginia Tech
Academics: Good. Not as good as GT, but a solid engineering school.
Athletics: Decent. Football has been good under Beamer but that is about it. They have become the dominant force in the DC area, but this team is SEC bound, count on it.
4) Georgia Tech
Acdemics: Excellent. Would fit in VERY well with the rest of the CIC, Purdue's kindred spirit of the South.
Athletics: Decent. Don't dominate the state, or even their market of Atlanta, but there is some alumni support. Would suffer in most sports in the B1G, becoming very Iowa-like (minus wrestling). Might get an offer, but would be contigent on landing UVA and UNC to provide some geographic continuity.
5) Maryland
Academics: Excellent and improving rapidly. UMD has pumped some SERIOUS money into their research and it is showing. They have shot up the ranks rather quickly but have a good foundation where it seems they are here to stay as an elite state flagship institution (on the same level as a Penn St).
Althetics: Eh. Facilities are crummy, fan support is crummy, don't even dominate their own market (VT owns most of the DC market and that would only go up if they go to the SEC). I say they get an offer to help geographically with some promises made to use the money to really push facilities upgrades. The UnderArmour connection should not be overlooked here.
6) Duke
Academics: Well, you know, they're Duke. Top notch.
Athletics: Better than you would expect. Many believe that the football team could get to ok from dismall, but it's the rest that intrigues. Most people forget that the BTN works so well because we have such good winter programming with nearly nightly basketball games, most that are actually REALLY good. Imagine what adding Duke to that would do? You bet your ass that people would be tuning in to see that. Get an offer contingent with UNC coming.
7) North Carolina
Academics: See Duke.
Athletics: Really the prize of the ACC. Very large fanbase, and a football program just waiting to dominate. They are in VERY fertile recruiting areas. If UNC can put up a fence like Tress did with Ohio, this could be an elite team in a matter of seasons. Add in top notch basketball and baseball, this is a no brainer. They WILL get an offer, probably from all 3 of SEC, B12, B1G.
8) Virginia
Academics: I always thought of UVA as the south's version of Michigan, just not full of assholes. VERY proud university with excellent academics. Anybody who is high-acheiving in the DC area wants to go here for school.
Athletics: Much like UNC, this is a sleeping giant. Right now the athletic department isn't putting the money where it needs to go, but one could argue that the ACC isn't really providing them with enough money to fight off VT. Another prime recruiting area that if UVA can dominate (the DC area), they will quickly become a solid program. I expect this to be the first offer the B1G makes.
The Cavs are a founding member and if they leave, that will truly be the end of the ACC. I expect FSU and Clemson to go making the ACC VERY weak. If the SEC grabs VT and NCSt (which I expect) then UVA may make the decision to leave. I could very well see ESPN coming in and stabilizing the ACC much like they did the B12 and allowing the ACC to add RU and UConn to get back to 12 (in addition to Cuse and Pitt). If that is the case, the ACC will survive. BUT, if UVA goes, then all bets are off. I personally thing that the SEC and B12 will go to 16 while the B1G and Pac12 stay at 12. No need to change. Let the dominoes fall a bit.