There are only two teams that make any sense to add to the Big Ten - ND and Missouri. ND has spurned the Big Ten twice, so I think the conference would be crazy to ask them again. Besides, ND is used to calling their own shots and would expect to dominate the conference, which would raise the hackles of the current dominators of the conference - OSU and UM. I see nothing but problems if ND joined. Missouri is interesting - good fit and seems interested. Everyone else (Pitt, WVU, Rutgers, Syracuse, Cincy, Louisville) are teams that the Big Ten would "settle for" in order to get the 12th team needed for a playoff. Adding any of these teams would dilute the conference - which is sort of like issuing new stock when the price is at an all time low.
Texas will never join - as soon as a move to the Big Ten was even whispered, there'd be a bill in the Texas State Legislature to ban the move. If Missouri doesn't join, the conference should go to plan B.
Has anyone thought about petitioning the Big Ten to allow the conference to split into a six team division and a five team division with the understanding that we'll add a 12th eventually. The NFL has four team divisions; MLB has had four and five team divisions for years; the NBA had four team divisions back in the day; the NFL has nothing but five team divisions. What the heck is so sacrosanct about six team divisions that the NCAA couldn't give the Big Ten a waiver?
If we can't get a waiver, then we should do some other things that keep the Big Ten in the picture in late November and early December - like play league games in indoor fields in Big Ten country, play some games in December in warmer climes (like why don't we schedule home and home games against Miami in December?), play a Big Ten opponent in FL in late November or early December (like in Jacksonville
Of course, all this flies in the face of the Big Ten's guiding principle - "thou shalt hold the OSU-UM game sacred and declare it to be the biggest game of the year", so it will have to happen only after all else fails and the league sees declining revenues. This is the same league that told PSU it would take five years to integrate us in the football schedules, resisted instant replay, and insists on finishing the season before Thanksgiving.