So in theory, based on the membership issues the WAC has dealt with over the past year, it wouldn't be a shock to see Lamar and SHSU join for a 12/14 WAC alignment. But for now, it appears Montana and MSU have the pole position with Lamar and SHSU being passed over in the near future.
I really like the idea of 12/14 because you can pull a divisional alignment that works for almost everyone:
East: LA Tech, Lamar, SHSU, UTA, UTSA, Texas St, and NMSU
West: Denver, Utah St, Montana St, Montana, Idaho, Seattle, and SJSU
That would be a very dangerous game, if the WAC took both Lamar and SHSU you know SFA would also be upgrading soon after, and if the East side of the league was to become successful they could easily attract UNT and ULL to join, and possibly even ULM (if LA Tech says okay), Arkansas St, and other possible upgrades like McNeese or Nichols St.
Basically you'll end up with a FBS verision of the Southland and Big Sky (after Portland St, UC Davis, Cal Poly, and others decide to move to the WAC).
That's the long term plan. I think Benson has said that he expects the conference to eventually split.