The Big 12 released a statement confirming the invitation and that negotiations will begin immediately with TCU. The University of Missouri did not participate in the vote on the advice of legal counsel.
Missouri didn't want to leave because the conference was down to 9 teams. They wanted to leave for a lot of the same reasons Texas A&M wanted to leave.If Missouri has a BCS conference to land in (and I'm not counting the Big East as a future BCS conference), they're gone.
It's just an embarassing reminder to everyone that it's a second tier BCS conference every time the name is mentioned. In fact, they should probably just go ahead and change the name anyway.
It's obviously an attempt to keep Missouri interested in the Big 12 and make it more appealing to prospective future conference members. We will see what will happen...