I was also thinking last night, if I wasn't so sure that they were just biding their time for the new Big East to invite more teams in the next couple seasons, shouldn't the Valley at least make a run at inviting St. Louis to join? They'd probably say no, but doesn't it at least make some sense? Outside of VCU, what's left in the A-10 you'd really consider a marquee program worth putting up with the horrible travel situation to be in a conference with? Even without Creighton you'd still have pretty decent mid-majors like Wichita St. and UNI in your conference. You'd have home court for your conference tournament. You're not constantly having your teams travelling to the east coast. And if the Valley decided they wanted to bring in say Belmont and Oral Roberts at the same time and go to 12, isn't that a conference you'd consider pretty level with a Butler/Temple/Xavier/Charlotee-less A-10 anyway? Obviously all bets are off if they think they're Big East bound in the near future, but it's at least food for thought, right?
SLU is the best option for the Valley if they are interested. They pretty much replace everthing Creighton brought to the table. They are even more isolated from the A10 geographically with Xavier leaving, so maybe they would be interested now. Dayton is still pretty close, but if I'm the Valley I invite them too.
Invite Nebraska-Omaha, South Dakota and South Dakota State to the MVC.
Again, replace one Omaha school for another and then fill the remaining two with schools that fit geographically.