Nothing will happen until the CUSA TV deal runs out then and the playoff deal is up for renegotiation, assuming the value of CUSA won't be much higher than the value of the SBC, I suspect you'll see some push from schools like Texas St, Arkansas St, ULL, and NMSU politicking to form a new regional conference ala the MAC. The timing would be difficult but I think at some point the Go5 conference not named the AAC/MWC are going to realize that flying from the Mid Atlantic to the Southeast to the Southwest isn't economically feasible unless your getting AAC/MWC money. The MAC has proved over the years that you can be successful in a regional conference and CUSA has proved that lot of markets does not equal success. Stay regional, spend the additional savings on coaches/facilities and focus on winning games and the ESPN contract will follow.
If there ever was a MWC style split with CUSA/SBC members, I'd suspect that it would be led by Texas St, who believe it or not, has more political capital than Rice, UTSA, and UTEP (only UNT has more) and if they could get support from a few key people I don't doubt this this could be a reality.
New Conference (?SWC?) - NMSU, UTEP, UTSA, TX St, Rice, UNT, Ark St, LA Tech, ULL
(9 leaves room for new members like Lamar, SHSU, SFA, or ULM, So Miss and possibly add UALR/UTA)
Every member brings value. CUSA members are obviously good, NMSU helps travel giving people a travel partner for UTEP, and ULL, Ark St, TX St (and GA St) are likely the best schools the SBC has to offer from a market/competitive standpoint and most likely be invited if the Big 12 raids the ACC who raids CUSA.
They could attempt to acquire So Miss, UAB, and GA St but that is likely a long shot as I think those schools would rather stay East than go West. But if it worked this new conference would clearly be a power player in from not only a competitive standpoint but also a market standpoint in the 2nd tier Go5 with representation in every Southern market from NM to GA not named Tennessee.
My best guess is that the rest of the conferences would shake out like this...
CUSA - So Miss, UAB, MTSU, WKU, GA St, FAU, FIU, UNCC, App St, ODU, JMU, Marshall
SBC aka "Upgrade City" - Idaho (fb only), Lamar, MO St, ULM, USA, Troy, GA So, EKU, Liberty, UMass (fb only)
Fan of the Big 12 Conference, the Mountain West Conference and...